Hi. This is NOT a bug in the app. If it were,  the volume of posts on this Community would have crashed the Sonos website by now. Going back to the previous version would make.no difference.

Just power cycle your router and Sonos as a first step. If that doesn't help,, uninstall the app, power cycle your.controller device and reinstall the Sonos app, selecting to join existing system. 

If that doesn't work, please post back for.further troubleshooting. 

Further thought.  Are your app AND system both fully up to date? Do a 'check for updates ' to make sure.

Thanks for trying to solve. Unfortunately I have already tried it all, without any luck.

If you’re continuing to have issues with the App and/or your Sonos devices and can easily reproduce them, but perhaps haven’t yet contacted Sonos Support, then maybe just give them a call.

Here is the link to contact them…

https://support.sonos.com/s/contact

Their App seems to be working okay here, but I guess different setups, hardware and Home networks can vary.

Note that ‘wifi interference ’ doesn’t necessarily mean inside your own sphere of influence. I once had interference caused by a new neighbor with a new WiFi router. And frankly, networks are designed to change as much as they can, which tends to be frequently, in order to avoid as much of that as possible, not to mention the constant ‘behind the scenes’ updates of the router’s operating system. The whole concept of ‘nothing has changed’ doesn’t make any sense to me. 

I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. But 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.

(sorry ​@John B , for jumping in)

I’ve spent hours on the phone with them. Much like most folks, no resolution. The only change was that Sonos made some kind of major update that ruined the experience for everyone. 

Hi

We live in the countryside - no neighbors or others, so interference is not the issue.

I have tried to contact Sonos Support, sending dozens of system diagnostics, but no help has come. 

I have even tried to ask Sonos to go back to the old app - but unfortunately not possible.

Maybe the only way is to give up Sonos