Plex doesn’t know where in your file episode 1 ends and epidemiology 2 begins. Plex simply reflects all the episodes contained in your file as individual episode entries. If you watched episode 1, the player should automatically mark episodes 1+2 as watched and progress to episode 3.
There’s a handful of feature suggestions asking for a different handling.
- One suggestion is asking for multi-episode files to be reflected with a single library item (e.g. labelled “Episodes 1-2” and “Fun Run (1) & Fun Run (2)” – with some intelligence it might even figure out to show that only as “Fun Run” – plus the combined descriptions of the individual episodes).
- Another suggestion is asking for a way to include timestamps/chapter references when each episode ends in the file name (though I suppose that’s not a super user friendly approach).
- Yet another suggestion is asking to guess the cut by assuming each episode has the same length and at least indicate the watch progress based on that
