I'm currently on arrowos 13. I wanted to go back to stock rom. So I tried flashing the fastboot rom via Mi Flash Tool. I got an error saying my device is locked. So, I checked if my bootloader was locked by using this command on fastboot " fastboot getvar unlocked" . It says "no", which means my bootloader is locked. I don't know how that happened. I tried to unlock the bootloader with Mi unlock tool, but it fails at the verification step itself. I don't how to proceed from here. I'm stuck with arrowos now.