With the iPhone 13 series Apple made the Face ID notch smaller. However, one change that was not publicized is that the each phone’s screen panel is linked to the Face ID system – if you replace the screen, Face ID will stop working. The culprit is a Tic Tac sized chip that now lives on the flex cable connecting the screen to the motherboard. There was no such chip before, so this wasn’t an issue. Of course, official Apple repair centers and shops that are part of Apple’s Independent Repair Program have access to proprietary tools that reprogram the chip to accept the new screen. The...
Source: https://www.gsmarena.com/ifixit_replacing_an_iphone_13_screen_at_a_thirdparty_repair_shop_disables_face_id-news-51718.php
