Screen keeps turning off when calling

Check theres nothing covering ur proximity sensor at the top of the phone, or it's not damaged… its part of the front camera flex, at the top of the phone just above the speaker hole there are a couple of areas that let light through to check when ur phone is up to ur ear and that turns off the screen whilst ur in a phone call. If too much light or too little light gets through then it causes issues with it either thinking ur face is against it or not working at all cos it cant detect the light.

Check for dirt, screen protectors, covers etc that may be in the way over there… :)