It becomes hard to follow-up because the thread hit the 1000 posts mark. Congrats, Plex team.
Not sure, if this behavior had been reported before:
In the morning I watched a movie while being in the bathroom using my tablet that got the New Experience version of the player.
I used the button to skip the intro, then chose a certain position of the movie (h264 mkv) on the timeline. Near the end of the movie, I skipped end credits.
I noticed that after Plex skipped end credits, it played the same movie from the beginning which is unwanted.
I did not willingly set a “repeat” option - I would not even know how to do it.
So, chances are good this is another bug.