Server Version#: 1.14.1.5488
Player Version#: Web player
In my library one movie takes ages to load. It loads for about 3 minutes, then plays 10 seconds, then loads again. It plays exactly 10 seconds every time.
I’m not sure if my hardware is too weak. It’s a Raspberry Pi 3 Model B with latest Raspbian (2018-11-13) and Linux 4.14.79-v7+.
The movie plays without problems on the iPhone app. All other movies and shows load quickly, except for this one.
You can check during playback if Plex attempts to transcode the video.
During playback, open Plex Web and click on Activity / Now Playing – when you hover over the icon representing your movie, Plex will display information on the playback and what is being transcoded (or not).