I found a perhaps relevant post here:
https://www.reddit.com/r/PleX/comments/wk2b7l/plex_changing_the_name_of_an_artist_in_my_music/
However the fix suggested didn’t work for me. I removed both artists, did the ‘plex dance’, then re-added the less famous artist. In this case, it classified him with the correct name (Villiers). However then when I added the famous artist back, it now classified him as Villiers instead of Lavilliers. I also saw this in the log:
“We have a matching item 59729 for the item we just set a GUID on (59733) ‘Bernard Lavilliers’ (index: 1)”
So it seems Plex is deciding these are the same artist and merging them. Is there a way I can prevent this?
