I recently moved. I set up the system a bit differently than at my old location.  I repurposed 2 one Sl’s that had been used as mono speakers in different rooms as surrounds to my arc. That works fine.  
 

However, one of the speakers (originally called dining room) continues to show up as dining room in Apple Music when I choose where to send the music.  The nonexistent speaker appears in Airplay on every device.  It’s confusing because I now have another speaker called dining room.  I temporarily renamed the active speaker so I can tell them apart.  I don’t see this as a good long term solution.

How do I get rid of the nonexistent dining room speaker in Apple Music?  Any help would be most appreciated.