Messaged you the new logs.
I also screen captured my process so you can see what I was doing, if you would want that.
It’s in video form though, so couldn’t send it here.
Oh wait. Are you using the Plex TV Series agent? If so, the setting to use local assets is in the library setting itself. Check that this is on. This setting is also available on a show-by-show basis, so check there too.
By making that change and refreshing metadata, one of the shows now plays their theme song. I will keep digging around, as you gave me a good starting point here.