У меня тоже не выходит мiui 12.5.2
Operation : Unlock BootLoader [ v2.27 ]
1. Make sure device is powered off. Power off, if need. Wait 20 seconds after
2. Insert USB cable in phone
Waiting for device connection ...
PTFN : MediaTek USB Port (COM51)
MODE : BOOTROM
PORT : 51
Waiting BOOT ack ...
BROM : Skip ACK verify
BROM : Init BROM
BROM init passed!
CHIP : MT6785 , SBID : 0x8A00 , HWVR : 0xCA00 , SWVR : 0x0000
CODE : Krug
TYPE : MODERN [RAPHAEL]
BROM : MEID : 73AD9AA68BD46B2A5D464CB42AA02649
BROM : SecLevel : 0x000000E7
BROM : SecMode : SBC+SLA+SDA+EXT
BROM : BROM|BL : 0x05|0xFE
BROM : BOOTROM
Error : Fail to init protocol!
>>> Device not supported for selected operation!
Reconnect Power/Cable!