MetroPCS, Hydro Wave. Sometimes I can't hangup. Proximity sensor is functional. Wifi calling is off. Power button ends call is on. Other times, I cannot make calls. I can dial, and it will ring. When the other end picks up, I hear the call hangup sound, you know that *beep* noise when a call ends. Instant hangup. Cannot answer calls either. I can call a voicemail, and when it "picks up" the same thing happens. Reseting phone fixes this, at least for a while. When I call certain people I get the cannot hangup thing almost every time. Android is updated, all apps are updated. I don't have any dialers or answering apps. Will be doing a factory reset tomorrow night when I have a full weekend to play around. Any help or information is appreciated.