Your current is CN ROM, go to download the Max Prim Global ROM (V10.2.2.0.NBDMIXM ) ...
JASPOJ 發表於 2021-6-29 13:17 [url=https://www.hkepc.com/forum/redirect.php?goto=findpost&pid=40468925&ptid=2625445]
at "Choose the ROM Image" screen, click on the ROM image you placed on downloaded_rom directory and the process should start updating right away. That was how I did my one!
Did you reset your phone at all since you have it? If you , you may be better to reset the phone by refreshing the ROM using the same app in you phone but choose to "download update" rather than "Choose Update Image",
I was referring to Built-in Update App on your phone for resting your phone with your current CN ROM,
You are using fastboot method. There should be a guide for MIUI ROM Flashing Tool