since I think a week or so, maybe related to a Homey update, pairing of my Sonos boxes in a flow is not possible anymore. When in a flow I use “Join the group of”, the error is “This device is not in a group”. When there is no group at all, this is clear, but then, it will never be possible to make a group…
Context by the way: I put all my Sonos boxes off at night and restart them in the morning. I even do a restart of the Sonos app before the pairing action itself. And I take some time for each box to pair.