Your naming and organization are nearly perfect, so just a few observations/suggestions:
- You should probably change those season folders to “Season 0x” instead of “S0x.” The docs are pretty specific on the point that season folders must be named this way and it may be throwing off your matching for later seasons.
- Since those are .mp4 files, ensure that any embedded metadata is correct; bad titles could interfere with matching. You can tell Plex to ignore any embedded metadata entirely by editing the library and disabling “Prefer local metadata” in its advanced settings.
- Ensure your library is pointed to /volume1/video/TV-Series/. It probably already is, but it’s worth mentioning.
If you do change your season folder names, it would probably be best to Plex Dance the entire series to force Plex to rematch it.
