When I AirPlay to my Apple TV from Android devices, it plays on the Apple TV for a very short while, like 1-2 seconds and then the Apple TV shows the AirPlay screen, with instructions for how to AirPlay content to it. On the Android Device, Plex seems to think that the video still plays on the Apple TV.
Android 6.0
Apple TV 3
Anyone knows what causes this? Wi-Fi is capable of streaming 5 1080P movies at the same time to 5 different devices. I tested.