Hi @AndyH2,
Sorry your post is slightly confusing to me, but I think you are referring to the Era Alexa voice assistant controlling Alexa ‘enabled Groups in the Amazon Alexa App? If so, then Amazon have not yet certified the Sonos Era 100/300 speakers to perform that function.

I assume Amazon certification has been applied for by Sonos, but Amazon are still to test/authorise the new Era products at the moment. That said however, the speakers can be used for playback and control, but you will need to include their room name in the voice instruction, or add them to an Alexa Group with a different enabling/controlling device (eg. Sonos One/Echo dot etc.) and speak the instruction to that controlling device.

Using that latter method the Sonos ‘Room’ name is not required, but note if you have more than one Sonos target speaker in that Alexa ‘enabled’ group, the speakers will all automatically group together to provide playback of the requested audio.

Hope that answers the question that I think you were asking here?

It’s not unusual by the way for Amazon to take 6 weeks or longer after Sonos release a new device to production before they go onto certify the product for enabling/controlling an Alexa Group and I can confirm that neither the Era 100 or 300 are yet certified.

Thanks for the reply. This has helped me make some progress. I don't consciously use Groups for Alexa controlled devices which seem to get confused with Rooms in the Sonos app. If I use the Amazon music app to connect to the Era 300 it is shown twice. Once as the Era and the second with the Room name. Using the Room name is successful unlike the Era device name. This stuff isn't obvious to the uninitiated!

I agree it can be quite a challenge for those not familiar with how the Alexa ‘enabled’ groups work with smart-home devices. I initially got to grips with them using Philips Hue lighting, so using them with Sonos seemed a little easier, once I realised how the controlling/audio-ducking/playback and auto-device-grouping worked, but certainly confusing for those not so familiar with the elements within the Alexa groups.

The thing that mislead me a little is that I also have an Arc and a Sonos One in 2 other 'Rooms' which have never had an issues. The Amazon Music app only shows & connects to these speakers under their Room names. Only the Era 300 is shown twice so maybe this is something to the lack of an Amazon certification for the Era 300.

In the Amazon Alexa App device list there are usually three entries or icons for a Sonos Home Theatre device as follows…

• A speaker device component
• An Alexa Voice Assistant component(s)
• A TV CEC control component

Each of the above has a separate and different looking icon next to it. The ‘Alexa VA components’ are usually embedded inside the properties of the ‘Speaker device component’. There can be several ‘Alexa VA components’ that’s if you add Alexa to the main HT player and its surrounds. The ‘TV CEC control’ icon is not embedded and always shows as a separate entry in the list.

It’s a similar thing for a stereo pair of ERA speakers, except there is no ‘TV CEC control’ component, so you may see one, two or three entries in the Amazon Alexa device list as it depends on if you install the Alexa voice assistant on one, or both, ERA speakers in the stereo pair. The ‘Alexa voice assistant component(s)’though will become embedded in the properties of the ‘speaker device component’ eventually, leaving you with just the one main entry/icon in the Amazon device list for the stereo pair.