I'm sure I must be missing something here but I find the Plex app on Apple TV REALLY confusing in terms of its navigation and its behaviours when selecting TV episodes to watch.
As an example I'm now into season 4 of the TV series '24'. Depending where I am in the app and select 24 I end up at all manner of different places. All I really want it to do by default is take me to where I stopped watch the last episode and, if I've mot finished it, carry on. If I have, load the next in sequence.
Instead I get either taken to Season 1, Episode 1 or Season 4, Episode 1 both of which I've already watched. One time the option came up to mark the first one as watched. I've already watched it so why is it even marked unwatched.
I'm sure it's just my lack of familiarity with it but at this rate I'll go back to iTunes I think, at least it doesn't throw me all over the place in the series. With Plex I seem to spend ages messing around trying to get to the right season. Previously I seem to have been able to get it to play one episode after the other. Not now though, I just get taken back the the episode screen and have to faff about with 'go to season' and then I can't even see from the scroll which episodes are watched or not, just a thumbnail for every one, which is about as much use as a chocolate fireguard. Talk about a confusing UI