Came across the same issue tonight, I had two XS units and 3 OEM screens. I found that for some reason, when I swapped the screens over one worked fine on one XS (XS_A)while the other one the top 3 row of icons was dead(XS_B). Yet I could swap another screen on XS_B and the screen would work fine. This proves that the logic board was fine & when I put the supposed half dead screen back on XS_A (original paired phone) the screen worked fine. The only difference I could see was…XS_A was on iOS 13.6 and XS_B was on iOS 14.1. Makes me wonder does iOS 14 have software checks that disables part of the screen if it’s not it’s originally paired screen…