I noticed this issue recently, I went to play some music on google play music and right when I hit the play button it instantly pauses. I figured it was just an issue with play music and haven't looked into it much yet. However, I just tried to play a video on the youtube player and it did the exact same thing. Restarting the device fixes this issue. I'm not sure what causes it, but it seems that it does it after being on for a while(2 days or so I would guess). Nothing that plays audio/video will play until a phone restart, the second I hit the little play icon it shows the pause icon for a split second then pauses and shows the play button again. I've had the phone for maybe two months now, I only noticed this happening maybe 2 weeks ago, not sure if it was doing it before that.