I did a quick search but haven’t seen anyone else mention this…
I believe this has been an issue since the last app update (Version 8.2) a little over a week ago. My devices - Atom, Muso2, and QB1 are all up to date.
This issue is present on both an iPhone and iPad mini running the app (both also up to date).
When using multiroom from either the Atom or Muso 2 to the QB1, there’s no longer a volume slider for the QB1. The multiroom function works but the volume on the QB1 has to be adjusted directly on the device, whereas the other devices each have a volume slider than can be adjusted from the app. This was not previously the case…
Did I miss some info regarding the latest version of the app? Can it no longer display the multiroom volume control for Gen 1 devices? Or is this a bug?

