I have a similar problem to the person here but with the TV show “Paw Patrol”.
In short, Sonarr wants to rename S01E01 to S01E01-02, despite the fact that thetvdb has a matching S01E01 entry. I’ve double checked the file and it’s exactly one episode long.
If I rename the file back to S01E01 then Plex happily finds the correct thetvdb metadata and displays it.
The problem isn’t limited to one episode and one season. However I’ve not had any issue with other shows, just Paw Patrol.
Could this be skyhook serving up old cached content?