回答“Changing the display glass”It’s possible, however really hard, and you might end up permanently damaging the display and digitizer while performing the repair.
回答“Fingerprint not working after screen replacement”I’d first check if the fingerprint sensor or the scan hole are dirty, and clean them. Afterwards, try erasing all the fingerprints and re-adding them. It’s possible that a software update started to pair displays to the motherboard, so one way of fixing this would be using a custom ROM. Hope this helps.
回答“Phone fell face down, screen is black but glass is ok”I’m pretty sure the actual display got damaged, but you can try opening your phone up and checking the ribbon cable, if it got partially unplugged. Though, I’d safely say that the screen is dead.
回答“Xiaomi Mi 9 v Mi 9 SE - build difference?”The Mi 9 SE is significantly smaller than the “standard” Mi 9. The display for one won’t fit the other, however, the guide applies to both devices, as it’s basically the usual way of display replacement. Good luck with your repair!