Whats the flash procedure?
Which firmware are you using?
My Flash Procedure -
1. TWRP - 3.2.3-4-arian
2. Wipe everything and of-course FORMAT Data
3. Reboot TWRP to recovery
4. Download and Copy the File given in Post #947
5. Flash it. No extra file/steps needed
6. Give it 5-7 minutes to Boot-up and Setup Miui.
7. After setting up Miui, Google account etc. Use it normally for 10/15 minutes.. (make a call or text or use the browser etc.) Then, Reboot the phone to system. Don't go to recovery.
8. After 2/3 minutes Reboot to TWRP and flash Magisk for Root. I use Version 17.2.
No specific Firmware requirement. (Not that I know of)