Apple blocked the ability of Sonos software to read ‘on this device’ data for iOS devices. You could, if your speakers support it, use the Apple Music (or pretty much any ‘on device’ player, which Sonos is not) to send an AirPlay 2 signal to your Sonos. Again, your Sonos device needs to support AirPlay 2 signals, early Sonos devices do not. I usually send the AirPlay 2 signals to either my Roam, or Ones, and group my PLAY:1s using the Sonos software when necessary.
Thanks for this response.
Apple has blocked this functionality, presumably to force subscriptions to Apple’s own paid music subscription?
Is there an effort to lobby Apple to change this?