Because your "guy" is buying cheap TFT displays or INCELL displays or Hard OLED displays like I have told you already will NOT work on iOS 16 (because they are NOT the same technology as OEM display ... they are cheaper to make... but not even that much cheaper... they go for 30-45 bucks and Soft OLED is 60-70)

you need to buy Soft OLED ( What I mean by that is YOU ( Soupylmao ) will have to buy that display ) on Aliexpress ( they have an App and website ) and THEN install it on your phone

THEN it will work

that is what I have to assume because I had the same problem with Hard OLED and now that I installed SOFT OLED it works ( as a reference TFT and Incell are THE WORST of them all ...and that is probably what your guy installed ...he gets a 10 pack of cheap displays for an even cheaper price so another cheap display wouldnt solve the problem)