LG G4 keeps locking the second I unlock it. Help!!

A

AC Question

So I just got a new screen for my phone, and I also got a screen protector. And now almost every time I unlock the phone it turns back off again. Is it an issue with something I put on the phone, or is it a software issue?

I tried looking it up on here but all there was was a thread about the same problem with the G3 and they said to get your finger off the proximity sensor, which I don't do. Help!!