I have a new Shield I got that randomly fast forwards a show/movie out of nowhere. It is like someone is holding down the fast-forward button. I have removed the battery from the tv remote, but there is nothing to remove from the controller so I can't isolate that until it runs out of battery but the controller is asleep and never really used.
What I notice when trying to stop it, frequently the Plex app will crash at the same time when stopping it and trying to rewind. I thought it might be a hardware issue but I'm starting to think it is software.