Well… I’m glad you already figured out 22 of those (1711 → 1733).
File naming can be a … pain… and yours aren’t necessarily spot-on. If your new server is using a different agent, this could cause some of the files to be recognized as sequential parts of the same movie (e.g. if their names contain - pt1, - pt2 or the likes). This way Plex will “stack” the files (1 movie spread across multiple files) and they won’t show as duplicates.
You can use some 3rd party tools to check where Plex placed your files. There’s e.g. WebTools-NG/ExportTools-NG which can give you a list of all the items in your library and their associated files.
