I have a Plex Pass Premium Music Library, but I wouldn’t think that is relevant
You can disable the genres for Last.FM under the Agents settings for both Albums and Artists. You can configure what extra information Last.FM will download.there. Click the little gear icon for Last.FM
Settings >> Agents >> Artists >> Last.fm
I also have “Local Media Assets” in the top position, above Last.fm, so Plex is supposed to use the embedded metadata first, then supplement with extra information from the agents.
Plex has a habit of refusing to update local metadata, so you might have to Plex Dance the Albums to see a change. Plex Dance info: The Plex Dance ™
I doubt it will fix your “bug” that the genre selection isn’t maintained when you switch from Album to Artist. The filters appear to be reset as @anon18523487 said earlier.
