Some of the shows eiter show more seasons that there actually is and some shows combine 2 or seasons as one

[tom80H]

If you fixed the file names since running into this issue you might need to perform a “Plex Dance” for Plex to “forget” it already knows those files.
When you scan files, Plex uses an algorithm to identify if a file is already in your database. This will check the actual filename but also the file’s size and a fingerprint. This feature is usually quite useful if you’re e.g. doing only minor fixes to your file names (without changing the structure / key content)… in your case it might have cause Plex to stick to the old mapping to season 19.

The Plex Dance ™

The purpose of this is to remove all cached metadata and xml data for an item that Plex usually keeps. This helps when you want to “start from scratch” for particular item move all files for the media item out of the directory your Library is looking at, so Plex will not “see” it anymore scan the library library (to detect changes) empty trash clean bundles (in menu next to server name, when accessed under ‘More’) double check naming schema and move files back scan the library Support articl…

Naming like this should be safe with Plex:

F:
  Series   <- your library is linked to this folder
    Roseanne
      Season 07
        Roseanne - s07e10 - Thanksgiving 1994.avi

There should be no need to look for bad embedded metadata with AVI files.