Have been trying to stream music simultaneously to a group of Amazon and Sonos Alexa enabled devices. I called Amazon and was told it was not possible. I called Sonos and was told it is possible.I uninstalled and reinstalled both apps. I can get the mixed devices in the same group, but not in the same multi-room music group.I had to set a preferred speaker in the group and it only streams there; not to my echo and dots. What am I doing wrong?