Verizon LG G4 volume randomly goes to mute, cannot find a reason

[AC Question]

Over perhaps the last month or two I have been missing calls, texts and notifications because my G4 has reduced its volume to minimum. I have not rooted this phone, and I can find no trend as to when this happens. It is in a case so the volume buttons do not touch a surface when it is laying on it's back. Just this morning I picked it up after sitting overnight and even though I left it on full volume it had gone to mute. It vibrates though.
Any ideas from the experts?

 

[B. Diddy]

Welcome to Android Central! Does this only happen when headphones are connected?

Also, it's possible the volume button is faulty, and perhaps intermittently registering false presses (regardless of position or pressure).