Actually I think it is in 3D. But it is very weired because the ouput of the video is splitted to left & right content. Also the menu of the TV is shown on both sides. Seems like the output of the TV is mirrored.
I have shot a photo with my phone. The windows at bottom left says 3D active. But the info is shown on both sides of the splitted screen.
Also I have created the 1Min of the movie. Unfortunately its 100MB big. How to share it?
Okay...I give up here, cuz your sample played perfectly on my 55ES8005
As such, I can only conclude, that the Samsung Plexapp, the PMS and the movie are all okay.
First thing I would do then, is to uninstall the PlexApp from your tv, and then unplug the power cord.
Wait 2 min, power up again, and reinstall Plex