Help Call ends when holding phone between ear and shoulder

[EmilyRN]

When I'm on a call and need my hands free I use my shoulder to hold the phone to my ear. Frequently the call ends from whatever part of my face, chin or cheek hits the end button. I've tried the "Power button ends call" but when I test that function it doesn't work. Does anyone know how I can lock the screen during a call or how to properly make "Power button ends call" work? Thanks a bunch! I have a Droid Ultra...

 

[doogald]

The screen shouldn't be on when the phone is held to your face. Do you have a screen protector or a case that is covering the proximity sensor, which is to the left of the earpiece at the top front of the phone?

 

[EmilyRN]

I do have a phone case but the sensor isn't covered up. I have hung up on my husband numerous times and I can't figure out how else I could end the call when it's held between my face and shoulder.