It’s possible, certainly, that there is nothing wrong with your WiFi. Unfortunately, that isn’t the only aspect of your network that could potentially be an issue.
Given the lack of substantive information, I’m going to suggest a duplicate IP address issue. Try unplugging all your Sonos devices from power. Reboot your router. Give the router a couple of minutes to boot back up before plugging in your Sonos devices.
If you continue to have issues, 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.