I am having this issue on my sets running Tizen 3.0. The specific TV where this repros constantly is a Samsung UN75MU630D.
Ended up enabling logging from the TV, and cranked up the logging to include DEBUG and am not seeing where it fails.
Another odd thing about the PreRoll videos on this set is that it will snip the last 2-3 seconds of the video/audio. Sets from the same year, but one generation older are not exhibiting these issues, and everything plays as expected including the movie.
TV Info:
Samsung UN75MU630D
OS: Tizen 3.0
Plex client: Latest
Cinema trailer playback was set to 0, tried at 1, same failure.
Can confirm. Plex server running Version 1.16.6.1592 and samsung TVs all have up to date plex apps. When a pre-roll ends it goes back to the movies main page instead of starting the movie. Have to have pre rolls turned off to use samsung tvs.