“Prefer local meta tags” in the properties of your music library.
After changing embedded meta tags, trigger “Refresh Metadata” on the album or artist.
If those changes were to an extent that the structure of the library is changed (e.g. different album artist), you may need a Plex Dance “light” (i.e. without step 4) to make Plex pickup the changes.
If none of the above makes any difference, you may need to verify the health of your server database:
