Unable to Play Sonos in Room Using iMac Controller

I have two rooms that I play music in. All Sonos operations in my Living Room work fine. But, when trying to play music in my upstairs office, when I select THAT room (Green Room), it does not appear to the left under the System heading. It remains Living Room and will play downstairs in that room.

I’ve deleted the Sonos Controller preference file and restarted the desktop version of the Sonos Controller but, to no avail. I see the music library in my Music Library/Folders but, once selected… nothing changes. Music will only play to the Living Room. I’ve also deleted and added back in the Green Room music folder.  Apparently my Controller is “Up to Date” version 13.0.