Performing the Plex Dance for one show should not affect other shows in the library.
Edit (pencil icon) one of the episodes of 11.22.63 and choose Info. That will show the path and file name. Post a screenshot.
Question: Do you have MP4 or MKV files? Plex will read embedded metadata from MP4 files if configured to do so. If the metadata is incorrect, it will cause matching & listing problems for Plex.
Edit the library → Advanced. Uncheck Prefer Local Metadata. Save changes & rescan the library.
Question: Which scanner & agent are selected (also on Advanced tab)? Plex TV Series / Plex Series are the defaults. Please advise if you are using something different.
One other thing to try. As a test, create a new TV show library. Add only the 11.22.63 show. Is it correctly recognized by Plex?
