@OttoKerner said:
OK, then I misunderstood earlier. Sorry for that!
No problem
This is what happened:
1.- Removed the show from the library folder
2.- Did The Plex Dance
3.- Renamed the titles to English and removed the hyphen from the files titles
4.- Added the show to the library folder
5.- Updated the library and…
6.- …Plex got a perfect match 
Curiously, Plex sets the hyphen back in the show title so it’s probably a problem sending a query with hyphens to The TVDB. It may help others in similar circumstances.
Many thanks, @OttoKerner and @JuiceWSA.
