Problems while on call

[DomSim]

My girlfriend has a moment which has the cl14 update and when ever she is on a call, the screen becomes active and she pushes every button with her face. She says the display is actually off and completely black and she cannot hear the button presses but when talking to her you get all sorts of dial tones. this also triggers the speaker phone, and mute functions quite frequently. we have taken the phone to sprint and they told her that her hair was in between the phone and the "heat sensor" obviously this guy was a moron. I have read the formerly hero only app "proximity sensor" works in a beta fashion now. anyone confirm or have any other suggestions?