Let’s start with the basics.
- you must use a folder structure like this: https://support.plex.tv/articles/200265296-adding-music-media-from-folders/
This applies explicitly also to sampler albums and compilation albums. - If you have 1), enable the display of “hidden” files AND those marked as “system”. Now look at the folder contents of the music library root folder and the artist folders which are affected. There should be no graphics files whatsoever in there. (Unless you have put in an artist picture consciously.)
Graphics files should (usually) only appear in the album level folders.
When trying to untangle things like this, it is very important to be aware of the status of “prefer local meta tags” (in the properties of the music library, on the Advanced tab).
See also I want a definitive solution to naming singles in Plex - #3 by OttoKerner for a deeper understanding of the organization of music in Plex.
After correcting the issue above, you’ll want to perform the Plex Dance “light” (“light”=omit step 4) with the affected artists/albums.
Start slowly and only add a few albums/artists at once and investigate if something comes out unexpected.
To speed up the process when dealing with a large number of items, you may want to disable the analysis features for music in plex (or at least defer them to be performed only during the nightly server maintenance period). https://support.plex.tv/articles/200289526-library/ (“Loudness”+“Sonic Features”)
