Glad you have things working.
FYI, on multi-part movies, not all Plex clients like them. If you run into issues it is sometimes best to just combine the parts together. Nothing to do with naming and organization. Just that some clients do not pick up the multiple parts well. See thread linked below.
Yeah, it happens. There are some movies that just don’t match well, match to other movies, etc. Usually happens when there are several remakes and Plex matches to a different release. Sometimes happens for seemingly random reasons. Fortunately those are few.
Again, glad you have things working. Cheers!