Echo Device Groups

@Declan, you can create “Multi-Room Music” (group) in Alexa, and add the group to SmartThings/Hubitat as an additional device via Echo Speaks. Once added to ST/HE, and authorized to SharpTools, you will be able to control this “group” device. However, there have been issues reported that Alexa can get confused when mixing the use of individual device and MRM groups, and not play the music on the device or group you specified. According to the feedback of the Echo Speaks developer, it seems to be a native issue that observed in the Alexa app as well.
See the discussion below for details.