Default LG Phone App no sound bug

I've been having this problem where I call someone or they call me and they can't hear me. The microphone seems to be working fine for Google Now and other stuff. But it's the Phone app that seems to be the problem. After a couple days of turning the volume to silent/normal/silent/normal, the Phone app's microphone becomes muted. People can't hear me when they call or I call.

This seems to be a bug in the LG phone app. Anyone ever have this problem?