Have you rebooted your router, followed by rebooting your Sonos? I’m not sure what ‘resetting the Sonos’ means, I hope it isn’t a factory reset, since that erases all data from the speakers that Sonos might use to assist. You haven’t mentioned any significant detail, either, such as version of the Sonos operating system, what your controller is running on, type of network, which speakers you’re having issues with, or if you’re running any ‘home control’ products. 

So, 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.