I have a Roam SL and 2 Play:1 speakers. All are correctly registered in the S2 app. I can freely group all speakers together in WiFi. The issue arrises when I stream music to the Roam over Bluetooth and then try to group with one of the other Play:1's. On the first attempt it works fine but then if I ingroup and then group again no sound comes from the Play:1, still plays on the Roam. The app shows the Play:1 as grouped and playing. If I power cycle the Play:1 and then regroup, it works again but the same happens if I ingroup.
Correction: I now get the same issue when connected over WiFi, was probably like that all along. So looks like the Roam groups the first time okay, after that not, either if on Bluetooth or not. Othe speakers group okay.
Extra: just found that the same thing happens after pausing playback, the Play:1 does not resume sound but the Roam does, still grouped on the app.