My MI 9T originally came with the Global EEA (10.3.12), then updated to 10.3.15.
I unlocked the bootloader and then installed TWRP 3.3.1-2 (PDA).
After format data (yes) and rebooting back to TWRP, I copied the ROM Xiaomi EU 9.9.26 and installed it (I did this process only with format data and...