When a movie finishes. It gets to screen that suggests other movies. If I hit the back button in the remote, nothing happens. The navigation menus that are typically on the left hand side are not there. My only option is to start one of the suggested movies, press back, and then I get the Home Screen with the menus etc.
I found that if I let the client sit on the screen after the movie/show ends and don’t use it for a bit(an hour or more) I can’t use the back button. I have pressed and hold the back button to have it take me to the Home screen of the Apple TV and then go back into the Plex app. After that it works.