It’s certainly possible there is some outside influence causing wifi interference. I’d certainly read that FAQ, and perhaps change the broadcast channel, but it’s not clear from your post whether you’re using SonosNet or your own WiFi connection.
Believe Im using SonosNet - But cant remember how you check that
Do you have one or more speakers directly wired to your router? If so, you’re using Sonos Net, and can change the channel in the Sonos controller. If you have no devices wired to your router directly, you’re using WiFi, and would change the channel in use on the routers control page.
In my past, I have had issues with both internally, with a failing microwave motor causing interference, and a new neighbor setting up their router on the same channel I was using for SonosNet. Took some investigation, but ultimately resolvable.