This statement is a little confusing.  Do you mean to say that you have an Alexa group setup, and the the ZP100 is setup as the speaker for that group?  When you say *NOT a speaker Group*, you’re talking about Sonos grouping feature, not tied to Alexa at all, correct?

Your Sonos speaker is receiving the ducking command from the echo. It’s not receiving a play-by-play of what’s happening on the Echo and deciding whether to duck or not.  In other words, you would need to talk to Amazon about why ducking isn’t happening for doorbell alerts.

Sounds like another question for Amazon.  You may find someone with an answer here, but Sonos isn’t really playing a big part in this and you are likely to get better answers on an Amazon forum then here.

Thanks for your response Danny

The reason I asked on here is that I understood that Ducking is a feature that Sonos were involved in the design of  and had tweaked several versions of Sonos firmware to get working correctly and my experience of Amazon Tech Support is that any interaction is pretty pointless as they are simply not structured as an organisation to deal with anything more than “Turn it off and on again” I find their support utterly hopeless.

This forum on the other hand I’ve found to be far more knowledgeable over the years

To clarify my position you have 2 options for grouping speakers on Alexa

The first option is a simple group where you tie an Alexa device to a piece of audio kit (Speaker, Bluetooth amp, Zone player etc) This is what I’ve done and my group purely consists of a ZP100 and an Echo with the ZP100 set as the default to play all music through that would otherwise play on the Echo. So if for instance you were an Apple Music subscriber you would ask the Echo to play something that would ordinarily play through the Echo but as grouping exists all music output is through the ZP100. Alexa’s response to your instruction  would be “Playing Apple Music……..on Sonos” and that response would play on the Echo immediately prior to the music beginning on the ZP100

“Combine Speaker” Groups on Alexa  is more to do with linking different Alexa products together in much the same way as multi room/zone linking in Sonos works, or linking two Alexa devices to create a stereo pair etc, this option is not applicable to my needs so I went for the “Standard” grouping as described above.

Putting my question another way……………. if I begin an interaction with Alexa by issuing the wake word then ducking on the ZP100 works exactly as it should immediately after the wake word in readiness to hear the rest of my voice command and ducking remains active until the interaction with Alexa is complete and the Echo returns to standby

BUT…..

The Ring doorbell being rung and Alexa Echos spoken response to this action “There’s someone at the Front Door” doesn’t involve the wake word but given that Alexa is talking I would ideally like ducking to become active but it doesn’t.

I’ve just extended my test scenario to a reminder set to trigger at a given time which will be announced on the Echo and again it doesn’t duck the ZP100 so the reminder is drowned out by the audio on the Sonos player.

Neither the reminder or the Ring scenarios are ideal.

My recollection is that if you actually hardwire the Echo into the ZP100 such that ALL audio comes out of the ZP100 speakers at all times then ducking becomes an issue as the wake word effectively mutes the ZP100 so that your interaction with Alexa can’t be heard as the speaker for the Echo is muted. unless of course this had now been solved by a firmware update?

The scenario's outlined above  seem so obviously bad that I’ve convinced myself i’m doing something wrong and was therefore looking for some advice

Cheers