Album tracks double

On my Plex client, I find an album which has every track twice. I go to the folder where I think that music is located, but every track/file exists only once. What’s the best way to debug/track down the root of the problem? Thanks!

This happens sometimes if you edit the Music library,
on the ‘Add Folders’ tab.
Make sure there are no overlapping folders in there.

Open the Plex media info of one such track and take a look which path Plex thinks has the second copy.
If both point at the same location, perform the Plex Dance “light” with this album
(“light” means, step 4 of the Dance can be omitted)