To all the people out there experienced in replacing screens I have this ongoing problem that the proximity sensor is inoperative after a screen change on an iPhone 6. I've done about 8 screens so far and only 3 have worked correctly. If I remove the sensor from the screen and place my finger over the sensor it works so its not the sensor.
A quick google of the issue suggests the inferior paint quality on the replacement screen like back in the day of the iphone 4 or placing tape over the back of the speaker as too much light is getting in.
Can anyone add to this with things to try as I'm 100% sure it is positioned correctly?