I was able to figure out the problem. i’m running the latest beta server for Emby, and there is a change (not sure exactly which beta version) in regards to music library organization in the server settings.
I didn’t realize that the Music & Kids Music libraries were set up in traditional Artist/Album/Song format in emby, whereas the Christmas Music library was set to ‘Other or Unstructured’. I removed the library, and re-added it to emby with the Artist/Album/Song format, re-synced the yatse DB, and everything is working as it should.
Apologies as this was an issue on my end and not on Yatse.
Merry Christmas!