Not sure what your subject line means.

In general, it sounds, without a lot of detail to be certain, like you’re experiencing wifi interference . I’d try, at least initially, a network reset, by unplugging all your Sonos devices from power. While they’re unplugged, reboot your router. Give the router a couple of minutes to settle down, then plug back in your Sonos devices. Give them a couple of minutes to boot up and reconnect, then check in your controller for any updates, and apply them. Finally, do your tests of Deezer again, to see if this process has fixed the issue.

However, if it doesn’t, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.