Plex Docs → Your Media → Naming and Organizing Your TV Show Files
Correct spelling and naming.
/NCIS (2003)/Season 19/NCIS (2003) - s19e02 - Nearly Departed.mp4
/NCIS Hawai’i (2021)/Season 01/NCIS Hawai’i (2021) - s01e02 - Boom.mp4
Plex Dance after renaming all episodes in both shows. Put them back into your library one show at a time.
If that does not work, put the TVDB ID in the show folder (not episode ) name.
/NCIS (2003) {tvdb-72108}/…
and
/NCIS Hawai’i (2021) {tvdb-401630}/…
Edit: Following up on @shark2k’s comments, both matched on my server without needing the TVDB ID.
