Hi Paul
My Sonos (S1) system looks like this from the Sonos end

There are 3 Sonos One speakers in the system the "Living Room" comprises a stereo paired set
and "Office" is a stand alone Sonos One (with Alexa).
From the B2 end, clicking on the Sonos button I see
Brennan Speakers
Office
Living Room
As selectable options.
MY PROBLEM
If I select "Living Room" from the B2 and play a CD Track, then I get a stereo sound for that track coming out of the paired speakers OK.
If I now press the pause button on the B2 UI the UI looks like this
BUT the Music continues to play until the end of the track AND the B2 controls ease to work for "Living Room".
If I restart the Web UI and go back to clicking the Sonos button I get this
NOTE that "Living Room" is greyed out and hovering the cursor over it causes a red "no entry" circle to appear.
Hope this helps
Fred