Hi @PHTP 

Thanks for posting in our business forum.

So, I can propose a way to find it whether that's true or not.

Here's the fact first, many manufacturers are not actually hosting the servers and they find big companies like MS and Google for their cloud service. The IPs are owned by them. So they host a server and the traffic goes to them. In your DPI, or any other form of stats, that might show up like it.

You can Wireshark and find out the IP address your Sonos uses. Find some and verify them by looking up their AS. AS will show you what the IP belongs to and who registered it.

If that IP was owned by someone else but not able to update it timely, you might see a different result in that DPI.

My best suggestions are Wiresharking and finding out the IP, look for ASN. And also consult the list of IPs you find with the Sonos.