Unable to un-merge original album and remastered version

Could you show me a view of all the meta tags and file name, similar to this:

If an album is merged from 2 different folders, Split should appear in the context menu:

(as you can see, I have even 3 different versions of that album.)
But I had “prefer local metatags” already ticked when I scanned these albums in. Which might make a difference.
Tick it again, then perform a Plex Dance light with all albums. Then add them one by one.