Apple TV 4 Photos - Slideshow Timing Limitations
No problem with AppleTV-3s. Only the AppleTV-4s have this issue. The
AppleTV-4s will not play photo slide shows with slide view times greater than 3
seconds. For slide view times greater than 3 seconds, the ATV-4 will show a few
slides and then reverts to the Slideshow set up screen.
How can this be fixed?
Apple TV 4K, tvOS 11