Yes sure i have the same problem when file explorer access root. When reboot it will go to fastboot loop.
System and Vendor go to read-only mode. And i try to replace file system via TWRP it can't.
Yes me too.
Redmi 5a that why i install twrp 3.2.4-2 and downgrade to 8.11.1 it better.
But still have problem when you full charging it will loop notify.