Basically did a screen replacement on my ATT iPhone 6+ and everything seems to function except for the ear speaker when the proximity sensor dims/turns off the screen. It'll either just hang the call up or stay silent and then after several seconds when the screen turns back on (pull my face away from the screen) it'll work again. I've taken it apart a couple times and the speaker flex cable seems fine and all the contacts are touching. Any ideas what it could be? THANK YOU!