Check out this screenshot. It is 100% including watched episodes. I have gone through every season three times and marked all watched episodes as played. I went to rebuild the smart collection after the final time and if you look, it is including watched episodes. What am I doing wrong? I switched the filter to Episodes to see what it was including.
I looked at my collection and it said there were 207 items. I marked about 50 as played. Went back and count was 207.
I didn’t save and try to edit an existing Smart Collection but I’ve had pretty good luck with them for Movies but had seen previous reports that TV Show Smart Collections may be a bit wonky still. Movies Smart Collections for example still have a bug where played matches status of server admin even if it’s a user looking at the collection… I believe that was exacerbated for TV Show Smart Collections.
If you make a new filter does it work fine and it’s just the Smart Collection that’s messing up? Sometimes it seems Smart Collections can get funny and you end up needing to recreate them.
Are you doing this though app.plex.tv or via local web host? The app.plex.tv seems to be a bit more reliable still for Smart Collection management as it’s higher level than the hosted (app.plex.tv is at Plex Web Version 4.64.3 and my Synology Hosted Plex is at Plex Web Version Version 4.62.1).
I’d try it from the app.plex.tv to see if it makes a difference (plus that will be one of the first troubleshooting steps Plex reps will request anyways).
Is it just this show? Might be a database thing and trying other shows might help pinpoint it if other shows are working with similar filters.
Does the filter work okay; if you mark an episode as watched while the filter is active and before you save it as a Smart Collection does it dynamically adjust there but the Smart Collection doesn’t once it’s saved as one?
I don’t know if it’d show up exactly, but if you mark a couple played\unplayed and wait a minute then upload the logs maybe that’ll help (I’m not very good at reading the logs myself but others definitely are). Reporting issues with Plex Media Server | Plex Support