New twist: I just happened to run into the following post:
It says that with with TV Series, the latest version of Plex stops picking up new episodes (is what I, and other in this thread, experience), but also that existing episodes dissappear (not seeing that). But also (drumroll) that when you rename the episode file to all lower-case, the episode does get picked up. And that works! 
They also mention that you have to put a number at the end of the filename, but I’m not seeing that. Anyway, I’ve been changing a couple of filenames to all lower-case and they’re now showing up in the library, so at least I’m good until a final fix comes along. @sa2000 Maybe it would be good to go over the forums to search for recent threads that are about issues in TV Series library/scanner and try to create a bigger picture for the Dev team. Cheers!
