Database Develop

[SOLVED] BRICKED S7 (G930FD) when going from v14.0 to v15 using updater in Magisk app

I had Magisk v14.0 running on my phone, which was installed using the patched_boot.img method. I had the stock recovery, stock ROM and kernel. But... a Magisk module I wanted to install required me to update Magisk, which I did using the in-app updater. On rebooting, the phone hung with a pulsating Samsung logo. I left it overnight to ensure it wasn't just a very long boot up.
I have seen a number of threads with people with the same solution. A fix appears to be to flash the latest Magisk-uninstaller zip then move back to Magisk 14.0. In order to do this, I flashed TWRP after reading the official thread but didn't swipe right (step 9 of the official guide) to allow system modifications and I didn't install SuperSU. I figured this may interfere with Magisk's systemless root. I did immediately flash no-verity-opt-encrypt-6.0 after flashing TWRP but I was still stuck at the pulsating Samsung logo. Since flashing TWRP, I have tried uninstalling Magisk, flashing no-verity-opt-encrypt-6.0 and reinstalling v14.0, v15.3, or removing Magisk completely. Doing combinations of these in the various sequences as suggested by those who have solved the issue from reading this thread and similar ones.
Should I allow TWRP to modify the system by swiping right and try the steps above again?
Assuming it's my boot.img that's cuasing this, I have tried signing but boot image with Chainfire's .zip that's mentioned here but that zip stopped flashing with an unexpected error.
The last thing I tried was to flash the original unpatched boot.img via TWRP. This gave a boot loop initially but when I reflashed it and immediately flashed no-verity-opt-encrypt-6.0, it progressed a bit further but got stuck at the pulsating Samsung logo again.
This thread shows someone who fixed the issue by installing a custom kernel. I haven't tried that yet. Is this a good idea?
I would be very grateful if you can suggest a way to repair my phone.

ssteward said:
I had Magisk v14.0 running on my phone, which was installed using the patched_boot.img method. I had the stock recovery, stock ROM and kernel. But... a Magisk module I wanted to install required me to update Magisk, which I did using the in-app updater. On rebooting, the phone hung with a pulsating Samsung logo. I left it overnight to ensure it wasn't just a very long boot up.
I have seen a number of threads with people with the same solution. A fix appears to be to flash the latest Magisk-uninstaller zip then move back to Magisk 14.0. In order to do this, I flashed TWRP after reading the official thread but didn't swipe right (step 9 of the official guide) to allow system modifications and I didn't install SuperSU. I figured this may interfere with Magisk's systemless root. I did immediately flash no-verity-opt-encrypt-6.0 after flashing TWRP but I was still stuck at the pulsating Samsung logo. Since flashing TWRP, I have tried uninstalling Magisk, flashing no-verity-opt-encrypt-6.0 and reinstalling v14.0, v15.3, or removing Magisk completely. Doing combinations of these in the various sequences as suggested by those who have solved the issue from reading this thread and similar ones.
Should I allow TWRP to modify the system by swiping right and try the steps above again?
Assuming it's my boot.img that's cuasing this, I have tried signing but boot image with Chainfire's .zip that's mentioned here but that zip stopped flashing with an unexpected error.
The last thing I tried was to flash the original unpatched boot.img via TWRP. This gave a boot loop initially but when I reflashed it and immediately flashed no-verity-opt-encrypt-6.0, it progressed a bit further but got stuck at the pulsating Samsung logo again.
This thread shows someone who fixed the issue by installing a custom kernel. I haven't tried that yet. Is this a good idea?
I would be very grateful if you can suggest a way to repair my phone.
Click to expand...
Click to collapse
Try flashing magisk 15.3 + no verity stuff as suggested on that thread...
Sent from my MI 5 using Tapatalk

ssteward said:
I had Magisk v14.0 running on my phone, which was installed using the patched_boot.img method. I had the stock recovery, stock ROM and kernel. But... a Magisk module I wanted to install required me to update Magisk, which I did using the in-app updater. On rebooting, the phone hung with a pulsating Samsung logo. I left it overnight to ensure it wasn't just a very long boot up.
I have seen a number of threads with people with the same solution. A fix appears to be to flash the latest Magisk-uninstaller zip then move back to Magisk 14.0. In order to do this, I flashed TWRP after reading the official thread but didn't swipe right (step 9 of the official guide) to allow system modifications and I didn't install SuperSU. I figured this may interfere with Magisk's systemless root. I did immediately flash no-verity-opt-encrypt-6.0 after flashing TWRP but I was still stuck at the pulsating Samsung logo. Since flashing TWRP, I have tried uninstalling Magisk, flashing no-verity-opt-encrypt-6.0 and reinstalling v14.0, v15.3, or removing Magisk completely. Doing combinations of these in the various sequences as suggested by those who have solved the issue from reading this thread and similar ones.
Should I allow TWRP to modify the system by swiping right and try the steps above again?
Assuming it's my boot.img that's cuasing this, I have tried signing but boot image with Chainfire's .zip that's mentioned here but that zip stopped flashing with an unexpected error.
The last thing I tried was to flash the original unpatched boot.img via TWRP. This gave a boot loop initially but when I reflashed it and immediately flashed no-verity-opt-encrypt-6.0, it progressed a bit further but got stuck at the pulsating Samsung logo again.
This thread shows someone who fixed the issue by installing a custom kernel. I haven't tried that yet. Is this a good idea?
I would be very grateful if you can suggest a way to repair my phone.
Click to expand...
Click to collapse
Dont flash unpatched boot images using twrp
flash unpatched boot image or v14 boot image(that you made earlier) using pc ODIN/ any other prefered tool. Just flash the boot.img nothing else or you can use fastboot to only flash boot.img, it works 100% all times,after flashing it should boot normal
then make a new patched boot image for v15.3 from magisk app just as you made for v14 and flash using pc,then it should boot normally
many phones seem to show stuck at boot logo after moving from v14 to v15(especially v15.1 and v15.2) and also some some devices with f2fs storage seems working weirdly with audio mods.

teddy0209 said:
Try flashing magisk 15.3 + no verity stuff as suggested on that thread...
Click to expand...
Click to collapse
I'm pretty sure that's one of the permutations I tried before but having just flashed those two zips again, after making sure any previous Magisk installations had been removed, I get the same result - stuck at the pulsating Samsung logo.
If someone can tell me what parts of the system the problematic in-app upgrade from v14.0 to v15.0 would have affected then I could perhaps have a better idea of what I need to fix to get my phone starting up again.

ssteward said:
I'm pretty sure that's one of the permutations I tried before but having just flashed those two zips again, after making sure any previous Magisk installations had been removed, I get the same result - stuck at the pulsating Samsung logo.
If someone can tell me what parts of the system the problematic in-app upgrade from v14.0 to v15.0 would have affected then I could perhaps have a better idea of what I need to fix to get my phone starting up again.
Click to expand...
Click to collapse
Have you tried flashing your stock boot image or even dirty flashing your entire system with ODIN (as suggested above)? Magisk only edits the boot image, nothing else.

Supreme Genius said:
Dont flash unpatched boot images using twrp
Click to expand...
Click to collapse
Sorry, my mistake. I did flash boot.img via Odin. It was the original boot.img file that I fed into Magisk v14.0 so it could create patched_boot.img.tar that originally worked. I'm going to try that again now.

Didgeridoohan said:
Have you tried flashing your stock boot image or even dirty flashing your entire system with ODIN (as suggested above)? Magisk only edits the boot image, nothing else.
Click to expand...
Click to collapse
That's good to know, thanks. I do have the full system from sammobile from which I extracted boot.img, so could try that if the 'lighter touch' approaches fail.

UPDATE:
After using TWRP to uninstall Magisk v15.3, which restores the stock boot.img, the phone hangs with a pulsating Samsung logo.
Using Odin to flash boot.img.tar (which I extracted from stock ROM) in the AP slot, I get a different behaviour - a boot loop which shows the "Samsung Galaxy S7 | powered by android" screen momentarily before going black and repeating.
So, even with a stock boot.img (assuming I've got the correct .img, which I'm pretty sure I have) and that I flashed it correctly, again, I think I have) then there seems to be more going on than just a corrupted/incorrect boot.img.
What next? A dirty flash of the stock rom?

ssteward said:
UPDATE:
After using TWRP to uninstall Magisk v15.3, which restores the stock boot.img, the phone hangs with a pulsating Samsung logo.
Using Odin to flash boot.img.tar (which I extracted from stock ROM) in the AP slot, I get a different behaviour - a boot loop which shows the "Samsung Galaxy S7 | powered by android" screen momentarily before going black and repeating.
So, even with a stock boot.img (assuming I've got the correct .img, which I'm pretty sure I have) and that I flashed it correctly, again, I think I have) then there seems to be more going on than just a corrupted/incorrect boot.img.
What next? A dirty flash of the stock rom?
Click to expand...
Click to collapse
Probably try that... Hope it's not a corrupt boot partition...
Sent from my MI 5 using Tapatalk

ssteward said:
UPDATE:
After using TWRP to uninstall Magisk v15.3, which restores the stock boot.img, the phone hangs with a pulsating Samsung logo.
Using Odin to flash boot.img.tar (which I extracted from stock ROM) in the AP slot, I get a different behaviour - a boot loop which shows the "Samsung Galaxy S7 | powered by android" screen momentarily before going black and repeating.
So, even with a stock boot.img (assuming I've got the correct .img, which I'm pretty sure I have) and that I flashed it correctly, again, I think I have) then there seems to be more going on than just a corrupted/incorrect boot.img.
What next? A dirty flash of the stock rom?
Click to expand...
Click to collapse
did you flash the previous v14 patched boot image again using ODIN? this should work
same boot loop problem prevailed on my s7 active and lenevo k8 and flashing the v14 patched boot image and then making new v15.3 boot image gave a perfectly working magisk, although my redmi 3 was showing same boot loop problem and i have to flash the stock rom ( used twrp to restore nandroid backup but boot loop was not solved )
It seems your lots of permutations and combinations have damaged post_fs config of the kernel so you have only option left is to dirty flash the ROM.

teddy0209 said:
Probably try that... Hope it's not a corrupt boot partition...
Click to expand...
Click to collapse
Sounds ominous. How would I recognise this and fix it?
Supreme Genius said:
did you flash the previous v14 patched boot image again using ODIN? this should work.
Click to expand...
Click to collapse
I don't seem to be able to find the patched_boot.img.tar that I used originally with Odin. I've checked a few different machines and on various SD cards but I only have the unpatched boot.img.

ssteward said:
Sounds ominous. How would I recognise this and fix it?
I don't seem to be able to find the patched_boot.img.tar that I used originally with Odin. I've checked a few different machines and on various SD cards but I only have the unpatched boot.img.
Click to expand...
Click to collapse
Then you need to flash the ROM , if you got another device then you can make a patched v15.3 image and flash it

I used another phone to created a patched_boot.img.tar for v15.3 and flashed that with Odin but that gave me a boot loop. Trying this again but flashing no-verity-opt-encrypt-6.0 afterwards allowed me to get to the pulsating Samsung logo. So giving up on this approach, I dirty flashed my stock ROM and this worked but I was left looking at a pulsating Samsung logo for a nerve-racking 5 mins or more.
Thank you everyone for your help. I have my phone booting up again!
Now I need to work out install the latest Magisk successfully. If I try using the patched_boot.img.tar method with v15.3 then I'm back to the pulsating Samsung logo. Again. Using TWRP to flash the v15.3 zip gives the pulsating Samsung logo. I did select 'Preserve AVB 2.0/dm-verity. I also tried again with a clean stock ROM install and flashed the v15.3 zip and no-verity-opt-encrypt-6.0, as suggested by someone who'd successfully installed v15.3. I'm at a bit of a loss.
One clue, TWRP couldn't see the internal SD card data (iow /data). I wasn't able to check this option in the 'Mount' menu in TWRP either. I think this points to /data being encrypted. TWRP could see it yesterday, so perhaps I've inadvertently encrypted this. I was careful to uncheck 'Preserve force encryption' in Magisk Manager. I guess now that I've unbricked my phone, I should start another thread for this magisk install issue but any help or pointers to relevant threads that I may have missed would be great.
Thanks again for all your help.

bootloop after flashing magisk 18 - PIXEL 3

went through the tutorial and everything went fine until magisk installation. stuck on loading screen forever. only complete wipe\installing twrp img helps to restore the system.
but then no root of course.
any ideas?

+1, I have the same error in havoc pie, in oreo magisk work fine?

subwoffer13 said:
went through the tutorial and everything went fine until magisk installation. stuck on loading screen forever. only complete wipe\installing twrp img helps to restore the system.
but then no root of course.
any ideas?
Click to expand...
Click to collapse
Could you provide information about your current setup as well as steps you performed to flash Magisk?

@topjohnwu have previously mentioned that it might not be a good idea to have TWRP installed along with Magisk on A/B devices (since the recovery is in the boot image). Use fastboot to boot TWRP and then install Magisk leaving the stock recovery untouched.

I have solved it by reinstalling stock os, and then when installing twrp and magisk , I didn't check "install twrp as system app" , as it suggests at the end of flashing . Bam , now I have twrp recovery and rooted phone .

[James] Moto E5 Play won't boot into Custom ROM(s)

Device variant: XT19121-2 James
Chipset: MSM8920
After repeated failed flashes I am on stock firmware using this guide. Phone boots and works normally right now, but I can't seem to flash any Custom ROMs on to my phone. I was using this post to flash Lineage OS 15.1, which worked successfully at first, but the WiFi wasn't working so I reflashed it. It still didn't work so I did it again, wiping Dalvik/Cache too. After the second flash attempt, my phone began to only flicker on and off. I made sure to always clean flash, factory resetting, wiping Cache and Dalvik, even formatting data, but no matter what I do it doesn't work. Also attempted other GSI images (arm, A-only) like AOSP, ResurrectionRemix and phhusson's Lineage OS 15.1 But they all failed too. I am using TWRP for James v 3.3.1 although I did also try other TWRP images like v 3.2.1 . But it makes no difference. Also used Magisk v19 like some guides suggested but whether I have Magisk or not, it doesn't work. Even made sure to push the fstab.qcom file to /vendor. Anytime a Custom ROM is flashed whether zip or GSI img it goes past the initial "bad key" or "N/A" screen and starts flickering on and off. Bootloader and TWRP works fine, but that's about it. Everytime a flash fails I go back to stock firmware (which always works) and try another ROM. I wonder why the first attempt worked but doesn't anymore even if I mirror the exact steps I took from stock. If anyone has any solutions I would be really grateful. Let me know if you need any more information.

have you taken any recent OTA updates?

mikeshutte said:
have you taken any recent OTA updates?
Click to expand...
Click to collapse
Nope. Still on the 8.0.0 version the stock firmware comes in.

tkhan7916 said:
Nope. Still on the 8.0.0 version the stock firmware comes in.
Click to expand...
Click to collapse
Okay give this a try, I'm assuming you have old root access and TWRP installed.
Download any Android 9 GSI of your liking, boot to TWRP.
Do a complete nandroid backup of the stock firmware.
Do a factory reset then wipe system partition.
Next flash your GSI that you downloaded to your system partition.
After flashing is complete of the GSI reboot to recovery.
After reboot completed flash your open Gapps zip. Then reflash Magisk.
if you get a error message when flashing g apps then you will need to use magic g apps with magisk as it will install them systemless. I have to do this on my device because the partition doesn't have enough space.
Give that a try and let me know how it goes if you have any questions feel free to ask.
---------- Post added at 10:09 PM ---------- Previous post was at 09:59 PM ----------
tkhan7916 said:
Nope. Still on the 8.0.0 version the stock firmware comes in.
Click to expand...
Click to collapse
mikeshutte said:
Okay give this a try, I'm assuming you have old root access and TWRP installed.
Download any Android 9 GSI of your liking, boot to TWRP.
Do a complete nandroid backup of the stock firmware.
Do a factory reset then wipe system partition.
Next flash your GSI that you downloaded to your system partition.
After flashing is complete of the GSI reboot to recovery.
After reboot completed flash your open Gapps zip. Then reflash Magisk.
if you get a error message when flashing g apps then you will need to use magic g apps with magisk as it will install them systemless. I have to do this on my device because the partition doesn't have enough space.
Give that a try and let me know how it goes if you have any questions feel free to ask.
Click to expand...
Click to collapse
I also just noticed you are using the latest version of TWRP 3.3.1. I'm not sure if you originally rooted and installed TWRP with the original patched version by Cody or not, but if so make sure with the new version that you format your data partition to f2fs. As this will ensure correct mounting of the data partition.

mikeshutte said:
Okay give this a try, I'm assuming you have old root access and TWRP installed.
Download any Android 9 GSI of your liking, boot to TWRP.
Do a complete nandroid backup of the stock firmware.
Do a factory reset then wipe system partition.
Next flash your GSI that you downloaded to your system partition.
After flashing is complete of the GSI reboot to recovery.
After reboot completed flash your open Gapps zip. Then reflash Magisk.
if you get a error message when flashing g apps then you will need to use magic g apps with magisk as it will install them systemless. I have to do this on my device because the partition doesn't have enough space.
Give that a try and let me know how it goes if you have any questions feel free to ask.
Click to expand...
Click to collapse
Followed these steps exactly, including formatting the data partition to f2fs, and the same problem still persists. Screen just keeps turning on and off in a loop without booting into the ROM. I downloaded the Lineage OS 16.0 GSI A-only Arm version for reference.

I am having the same issue
Using XT1921-1
Latest TWRP
Have tried LOS 15, LOS 16, AOSP 8.1, AOSP 9.0
Have tried flashing in fastboot and TWRP
Have tried every combo of wipe/factory reset/format data and magisk flash possible
have tried stock recovery, have tried no verity, have tried stock boot.img
nothing works. only able to produce powered on (black and blank) screen that turns on and off for a minute before returning to bootloader
PLEASE HELP
think i might need a 8.0 GSI but cant find one anywhere

I eventually got RR to boot on the james xt-1921-3 I installed XT1921-3_JAMES_T_MPCS_8.0.0_OCPS27.91-150-5-1-3_cid21 as a base, then used boot and vendor partitions from JAMES_T_OCP27.91-51-4_cid21_subsidy-TMO_RSU_regulatory-DEFAULT_CFC and it finally worked.

tkhan7916 said:
Followed these steps exactly, including formatting the data partition to f2fs, and the same problem still persists. Screen just keeps turning on and off in a loop without booting into the ROM. I downloaded the Lineage OS 16.0 GSI A-only Arm version for reference.
Click to expand...
Click to collapse
Message me, I'll host a TWRP backup for the XT-1921-3 that boots RR 6.1

Download the file from this post https://forum.xda-developers.com/android/software/universal-dm-verity-forceencrypt-t3817389 , then using fastboot, flash the vendor and boot img
fastboot flash vendor vendor.img
fastboot flash boot boot.img
then boot into recovery and flash the file from that post to disable dm-verity and force encrytion, after that flash magisk, then reboot to bootloader, at command prompt-
fastboot erase userdata
fastboot erase cache
fastboot reboot
that should get you booted - profit

mrbox23 said:
Message me, I'll host a TWRP backup for the XT-1921-3 that boots RR 6.1
Click to expand...
Click to collapse
Do you still have that back up by any chance and could ypu send it to me?

TWRP gets replaced by stock recovery

So I've used TWRP r16 and it throws an "Image not signed or corrupt" error as suggested by other users I ignored it, but everytime I reboot to system and try to get to recovery "no command" show's up meaning TWRP was replaced by stock recovery all help will be appreciated.
Thanks

Akash731 said:
So I've used TWRP r16 and it throws an "Image not signed or corrupt" error as suggested by other users I ignored it, but everytime I reboot to system and try to get to recovery "no command" show's up meaning TWRP was replaced by stock recovery all help will be appreciated.
Thanks
Click to expand...
Click to collapse
You need to flash Magisk after flashing TWRP
1. Flash Latest TWRP
2. Reboot to TWRP
3. Flash Magisk
If you boot in to system after flashing TWRP, TWRP will be removed

pradeeppk said:
You need to flash Magisk after flashing TWRP
1. Flash Latest TWRP
2. Reboot to TWRP
3. Flash Magisk
If you boot in to system after flashing TWRP, TWRP will be removed
Click to expand...
Click to collapse
Hey thanks that worked.
But everytime I boot to system and boot to twrp the data gets encrypted and I can't access the files do you happen to know any solution for this?

Akash731 said:
Hey thanks that worked.
But everytime I boot to system and boot to twrp the data gets encrypted and I can't access the files do you happen to know any solution for this?
Click to expand...
Click to collapse
If you are on stock Rom, according to my knoweldge it is not possible to remove encryption, if you format your date in twrp for removing encryption then reboot to system you can see that the phone is again encrypted.
But in custom roms this doesnt happen.

pradeeppk said:
You need to flash Magisk after flashing TWRP
1. Flash Latest TWRP
2. Reboot to TWRP
3. Flash Magisk
If you boot in to system after flashing TWRP, TWRP will be removed
Click to expand...
Click to collapse
pradeeppk said:
If you are on stock Rom, according to my knoweldge it is not possible to remove encryption, if you format your date in twrp for removing encryption then reboot to system you can see that the phone is again encrypted.
But in custom roms this doesnt happen.
Click to expand...
Click to collapse
I don't want to try custom rom's as this is my main device guess I'm stuck with the encryption then thanks for your help. :good:
Edit:-
Tried TWRP r20 it decrypts fine thanks

pradeeppk said:
You need to flash Magisk after flashing TWRP
1. Flash Latest TWRP
2. Reboot to TWRP
3. Flash Magisk
If you boot in to system after flashing TWRP, TWRP will be removed
Click to expand...
Click to collapse
You don't have to flash Magisk after flashing TWRP. The two are unrelated.
After flashing TWRP you have to boot into recovery, not system. Once TWRP was started, you can reboot into system. No need for Magisk (unless you want Magisk anyway).

gewe said:
You don't have to flash Magisk after flashing TWRP. The two are unrelated.
After flashing TWRP you have to boot into recovery, not system. Once TWRP was started, you can reboot into system. No need for Magisk (unless you want Magisk anyway).
Click to expand...
Click to collapse
It will not work in stock ROM, if you flash a custom rom there is no need to flash Magisk.
You should flash Magisk or custom kernel after flashing TWRP otherwise it will be erased.
Google about TWRP erasing after reboot you should get too many posts regarding this
This is one of them
https://forum.xda-developers.com/oneplus-3t/help/twrp-deleted-booting-t3769867

pradeeppk said:
It will not work in stock ROM, if you flash a custom rom there is no need to flash Magisk.
You should flash Magisk or custom kernel after flashing TWRP otherwise it will be erased.
Google about TWRP erasing after reboot you should get too many posts regarding this
This is one of them
https://forum.xda-developers.com/oneplus-3t/help/twrp-deleted-booting-t3769867
Click to expand...
Click to collapse
I am using stock ROM, and yes, also Magisk (installed later). IIRC Magisk is not needed for TWRP to work. When I receive the next OTA notification, I will test this.
The thread you are referring to is for a OnePlus 3T. For our device this is the thread: https://forum.xda-developers.com/moto-g5s-plus/development/recovery-twrp-3-1-1-r7-t3694910.
Since there is no official TWRP for the Moto G5S Plus, I took the following text from the TWRP page for the Moto G5S.
Note many devices will replace your custom recovery automatically during first boot. To prevent this, use Google to find the proper key combo to enter recovery. After typing fastboot reboot, hold the key combo and boot to TWRP. Once TWRP is booted, TWRP will patch the stock ROM to prevent the stock ROM from replacing TWRP. If you don't follow this step, you will have to repeat the install.
Click to expand...
Click to collapse
Instead of that you can also use fastboot reboot-bootloader, and then from the bootloader start recovery.

pradeeppk said:
It will not work in stock ROM, if you flash a custom rom there is no need to flash Magisk.
You should flash Magisk or custom kernel after flashing TWRP otherwise it will be erased.
Google about TWRP erasing after reboot you should get too many posts regarding this
This is one of them
https://forum.xda-developers.com/oneplus-3t/help/twrp-deleted-booting-t3769867
Click to expand...
Click to collapse
Two days ago I received a notification for an OTA update, containing the August 2019 security patches.
After going back to stock ROM, installing all the updates up to the latest, I installed TWRP. After booting into recovery, and then into system, and recovery again, TWRP was gone. Strange, I don't remember this happening before. Maybe I always installed Magisk before booting into system.
Bottom line: you were right, I was wrong. Thanks for pointing it out.

gewe said:
Two days ago I received a notification for an OTA update, containing the August 2019 security patches.
After going back to stock ROM, installing all the updates up to the latest, I installed TWRP. After booting into recovery, and then into system, and recovery again, TWRP was gone. Strange, I don't remember this happening before. Maybe I always installed Magisk before booting into system.
Bottom line: you were right, I was wrong. Thanks for pointing it out.
Click to expand...
Click to collapse
As like you said this is the first time in my life i need to flash magisk to stick twrp.
I usualy doesn't use root or custom roms, install twrp, remove unnecessary apps from stock system, replace host files with adaway hosts, replace or edit gps config files. and continue using stock.
This is the main routine from Android 1.5
(Samsung spica (i think it was the first Android phone from Samsung)).
It may be due to security reason stock kernel or system delete twrp.
When installing magisk it patch stock boot image, that may be the reason of twrp remains after flashing magisk.

Help with Magisk root Pixel 2 factory Android 9.0.0 installed

Hello,
I have been struggling to root my device. I have not wiped and rooted it in some time and now coming back to it again magisk keeps breaking my device.
I have clean flashed the latest android 9.0.0 build. I have flashed TWRP custom recovery 3.3.0 successfully. I have tried to flash magisk 3 times now and afterwards my phone wont boot. I originally used magisk manager to get the latest zip and patch my boot image. I then rebooted to to bootloader and ran fast boot flash boot patched_Magisk.img. This wiped out my twrp recovery and my phone wouldn't boot, i couldn't get back into twrp recovery. I reflashed latest 9.0 build and wiped everything. I flashed twrp again and tried to flash Magisk 20.0 from recovery. It was successful but again i couldn't boot into my phone and it eventually restarted back into recovery which i still had twrp this time. I then tried it again with 19.3 and the same thing happened. can anyone tell me what is going on here? What am I missing? I have been having reflash factory 9.0 build each time just to get it to remove the patched boot image and boot up again.

Was either the TWRP version or the two check boxes it has now to install twrp app as system. Installed 3.2.3-1 and didnt install the twrp app through the recovery check boxes and it worked.