If you've flashed a non-stock recovery like TWRP*, you can not use the OTA update feature. You need to flash the full ROM via TWRP.
* TWRP is now officially supported, make sure you flash that version if you're using an older, unofficial TWRP.
I've turned my phone setup into a script + instructions, if anyone cares here's the thing - https://gitlab.com/C0rn3j/C0rn3j/blob/master/androidSetup.sh
It has more detailed pm uninstall list than the OP at least.
TWRP(Russian - twrp-3.3.1-2-davinci-fix) Flashed to it without issues from 10.3.15.0.PFJEUXM.
EDIT: To get rid of the new "Services & Feedback" app, run adb shell pm uninstall -k --user 0 com.miui.miservice
My full ...
1) Can't change battery status to circle nor circle with percentage on. - it just doesn't show up
2) I have opened File Manager, navigated to my SD card and tapped on...
What twrp version worked for you?? I tried with the Chinese and with the Greek one and the phone it's stucked on the boot logo after flashing this zip....
I used "TWRP for Xiaomi Redmi K20/Mi 9T by brigudav (twrp-3.3.1-2-davinci-fix)" Which seems ...