On a second look, it actually seems like it is not the case that “the Movies library show an item for basically every individual TV Series episode”, rather it is showing an item for every TV Series episode that doesn’t appear in the TV Shows library. So I guess it is related to this thread: 1.32.1.6999 not adding new episodes/shows for TV
I hope/guess that if/when that is solved I will continue to be “extremely lucky”.