It helps tremendously if at least the first track from this artist
that is added into Plex has the correct spelling in its embedded metadata.
You could also use the ‘Fix Match’ command at the artist level. (you might have to attempt this twice)
Many of these issues can indeed be circumvented if you rely primarily on your own embedded metadata. (Provided you have them in order.)
Settings - Server - Agents - Albums - last.fm
Drag the line ‘Local Media Assets’ into the topmost spot (make sure it has a checkmark first)
Edit the music library(s), go to the ‘Advanced’ tab and put a checkmark into ‘Use embedded tags’
^^^ these changes don’t affect items rectroactively, which were already added into Plex.
You’ll have to perform the Plex Dance to see an effect on “old” media.
(with music, you can omit step 4 of the ‘dance’)
