@ka9yhd, so the cheap screen they put in probably didnt have a transparent space for the prox sensor, OR the screen fit so poorly that the sensor would slide back a bit, OR the screen fit so poorly at the bottom that the prox sensor was literally disconnected when they put the screen back on.

ive bought screens with all 3 of those problems in the past. the solution for no transparent space is to turn off the prox or get a new screen. the solution for poor fit is to put tape on the wire, and then use small tools to push both ends of the prox in place right before closing the phone. its tricky af.