Hi @ClarkE, thank you for reaching back to the Sonos community. 
I appreciate your detailed post describing the issue as well as the steps that you did, let me help and try to figure this out.

I’ll be asking questions to isolate the issue so we can create a path towards resolution.

1. To isolate the issue, have you tried turning off your Echo Dot? Did you notice that the music stop or give you an error message?
2. Have you rebooted your router, all Sonos devices, and mobile controller to refresh the connection?
3. Did you experience the same on other music services?

It would be great if you can submit a diagnostic of your system and reply back with the confirmation number. This will allow us to see how your system is functioning, and help provide a resolution since we don't have access to your existing ticket number.

If you need help with any other information, please be sure to let us know.

We'll wait for your reply.

So the Sonos techs helping me kept asking about anything that could cause interference, and I realized the Echo Dot could do that. So I pulled the plug, and voila Sonos worked- no drops.

Now it gets complicated. Last night I finally decided to chat with Amazon, and the tech support woman was very helpful. I realized that my Control (the Sonos product with the interference) wasn’t part of the Amazon network- wasn’t a preferred speaker. One click in a check box and voila- problem solved! So now my Sonos works great and can talk to Alexa. Can’t get different speakers to play different sources using Alexa yet. 

At this point, I feel as though I never really understood how Alexa and Sonos interact. I am thinking of  some form of a do-over- taking Alexa off Sonos completely, then trying to attach Alexa in a different way. The use of groups somehow escaped my understanding.

My main goal is to keep Sonos doing what it does best. If I can’t get Alexa to work with Sonos, goodbye Alexa. I will be consulting the Sonos Community for help, as well as Alexa chat (which was very helpful).

Diagnostics submitted- number 385388982. Have not rebooted router or Sonos devices. What is a mobile controller- my Android cell phone I used to set up Sonos devices? And the dropping seemed to only occur with SiriusXM, but I listen to SiriusXM Ch. 76 Symphony Hall constantly.

I am now working with Sonos as a wired system- one One speaker is connected to my modem router by Ethernet. That might affect how Sonos interacts with Alexa.

Thank you for your interest!

Hi @ClarkE, thank you for your detailed response and for providing the diagnostic, let me check it for you. 

As per checking, Alexa was successfully set up with your Sonos enabled-speakers. There shouldn’t be any reasons for it not to work.

You can use Alexa with Sonos voice-enabled speakers. After Alexa is set up, you can try some commands to play music on Sonos, control your home theater products, and check Alexa announcements. You can also set up some Alexa Groups for a more seamless experience. If you’re giving a command to Sonos using an Alexa-enabled device like an Echo Dot, you’ll need to include the room name in your command unless your Sonos speaker is part of an Alexa group.

If you’re having trouble using Amazon Alexa with Sonos, check our troubleshooting article for some help.

If you’re still experiencing the same, I recommend contacting back our Sonos Customer Care support to remotely connect to your device to further assist you with this to provide the best option for you.

Please feel free to reach out in the future if you have any other questions.

You're always welcome here.

Thanks for the reply! This morning I rebooted the modem/router and all four Sonos components. I took Alexa off Sonos last night, but after rebooting I put her back. I simplified groups, and now the system seems to be working fine. I can control using either Alexa or Sonos. In fact, Alexa doesn’t talk directly to Control, but I can still play music controlled by Alexa because Alexa communicates via Sonos, or so the app says.

Thank you for your help. I love my Sonos system!

Hi @ClarkE, thank you for updating us. I’m glad that your system is working now.

Please feel free to reach out in the future if you have any other questions.

The Sonos Community is always here to help.