Instructions for keeping twrp and root after updating the UL USER rom:

[dungnghien]

1. Download resources:
a. Download the rom UL USER, leave it there and do nothing to it yet.
b. Download the twrp.zip file https://mega.nz/#!l8BXgaDL!Y1AH5TM9jKI5r6LtEKFN_4Po105glHNR602yVDipfF8 (if you still have twrp installed beforehand)
c. Magisk 20.0 https://github.com/topjohnwu/Magisk/releases/download/v20.0/Magisk-v20.0.zip
2. Proceed:
Do not update the UL USER rom from the device's interface (SYSTEM UI), power off, boot into TWRP. Select install zip in the following order:
a. Rom UL USER
b. Twrp.zip
c. Magisk v20.0 (or exit the main menu, select Advanced, install root also)
Done, exit the main menu select advanced wipe, wipe cache, dalvik.
Reboot the device.
Done.
By chicken

 

[MyronAz]

This did not completely work for me going from .35 to .64. All the steps completed successfully but when I rebooted the phone, Magisk was not installed so I didn't have root. I was able to then boot to TWRP and successfully install Magisk, but I don't know why it didn't work the first time. Anyone else try this? Did it work as intended for you?
One other thing I noticed - TWRP no longer has an option to wipe the cache under wipe > advanced, only for Dalvik/ART cache. Why?

 

[Nyuha]

Wish I would have tried this before i updated and lost root, i flashed a root boot.img with fastboot now im bricked and don't know what to do.

EDIT: got twrp did a factory reset and im in now.

 

[jimdorky]

1. Download resources:
a. Download the rom UL USER, leave it there and do nothing to it yet.
b. Download the twrp.zip file https://mega.nz/#!l8BXgaDL!Y1AH5TM9jKI5r6LtEKFN_4Po105glHNR602yVDipfF8 (if you still have twrp installed beforehand)
c. Magisk 20.0 https://github.com/topjohnwu/Magisk/releases/download/v20.0/Magisk-v20.0.zip
2. Proceed:
Do not update the UL USER rom from the device's interface (SYSTEM UI), power off, boot into TWRP. Select install zip in the following order:
a. Rom UL USER
b. Twrp.zip
c. Magisk v20.0 (or exit the main menu, select Advanced, install root also)
Done, exit the main menu select advanced wipe, wipe cache, dalvik.
Reboot the device.
Done.
By chicken

In my experience after install back twrp reboot back to recovery (twrp) before flashing magisk .

 

[MyronAz]

Does this work when updating to A10?