For TV shows, Plex uses the TMDB or TVDB ID. IMDB is not supported.
Also, the season folder should be named “Season 01.”
If you follow the documentation it works.
Rename per the documentation and, if necessary, Plex Dance the show.
EDIT: One more thing to check.
Plex can read embedded metadata from MP4 files. If the metadata is incorrect, Plex will not display the show correctly.
To tell Plex to ignore embedded metadata:
- Edit the TV show library
- Advanced
- Deselect
Prefer Local Metadata. - Save changes & refresh metadata if Plex does not do so automatically.
