If you try updating with magisk patched boot flashed you will get error 20
If you directly installed magisk, the procedure to do is open magisk, press uninstall and then restore stock images, DO NOT REBOOT, perform the ota update or the dialer update.
If you are doing the ota update from the settings notification wait until it ask to reboot, still do not reboot, open magisk, install it by selecting the ota option, after it finishes return to the settings update menu and restart from there.
When it boots up you are on new fw with patched boot.
Redo all the steps until you are at the version you want.
If you do the dialer update, BEWARE because the phone reboots on its own
Start the dialer update and keep an eye on the phone. When it powers off hold vol down to boot into bootloader and BOOT the magisk patched boot img of the new fw
So the phone has stock boot flashed but patched boot booted, you can perform a new update as soon as you boot it, because the phone has stock partitions on it.
With the dialer always remember vol down at boot and boot the new patched img.
Let us know how it goes.
