What is the directory structure for your shows and how do you have the shows named?
Plex is very picky about TV shows. You should follow the recommended directory and naming structures. See Your Media, specifically, Naming and Organizing Your TV Show Files.
If you modify your directory structure or file names, you will need to Plex Dance the shows. This clears the incorrect information out of the Plex database.
Also, make sure you have the files in a “TV Show” library, not “Movies” or “Other Videos.” If in the wrong library type, Plex will definitely have trouble correctly identifying the shows.
Note that Plex matches show & episode names against TheTVDB.com. Use the same show name, etc for best results.
