I’ve been having the same problem for a few weeks now, latest updates:
PMS 1.32.8.7639
Apple TV 8.29.
It occurs when watching simultaneous episodes of a single series in a queue. I experience it whether shuffling or playing any series, so I think it’s related to the queue handling.
When the first episode ends and the video minimizes to the post-play screen, the next episode button is highlighted and clicking the remote plays the next episode.
However for all subsequent episodes in the same queue session, clicking the Next Episode button does nothing, and will not progress until the credits/file has ended and the 15 second countdown timer starts. Then the next episode can be played by clicking the remote button.
If I reopen the video window while the credits are rolling, and skip to the end of the file to cause the countdown timer to trigger, then I can progress to the next episode.
If I instead exit the play queue back to the home/series screen and reopen the next episode manually, the process restarts. At the end of that episode, the next button will work the first time again without waiting for the countdown to start, but all subsequent episodes will be blocked in the same manner until the credits end and the timer starts.
Seeing the release notes fixed 'Prevent skipping episodes with multiple taps to play button on post play", I suspect it has something to do with this area.