So it seems like ANY UHD video I attempt to play on the prime video app just sits there and spins as if the video is loading. It never loads and says the video cannot be played at this time. I have no clue what's going on. It's not a bandwidth issue - I have a gig connection and play 4K fine on Netflix and from the Apple Store. All the other videos on the Prime app play fine. But basically anything that has the UHD tag on it will simply not load. Any ideas? I've rebooted the Apple TV, uninstalled, reinstalled the app.. associated disassociated my account, etc...