On my 6P when I try to make a call my screen goes black.

[AC Question]

When I try and make a call the screen goes black. The call does go through.
Only way to stop call is to hold down power button.
Have tried safe mode and factory reset, no luck.

 

[hallux]

Do you have a screen protector on the phone? Some did not have the cutout for the proximity sensor, so when on a call it will turn the screen off..