If you have a Sonos Play:1 close by, or it’s too close to the router, then move the Boost as far away as practicable from both - you could have (perhaps ?) wired just the Play: 1 to the router instead of the Boost, but that all depends on the purpose of the speaker in your setup.

Anyhow what you need to do after that is log onto the routers configuration/setup pages through a web browser or perhaps through any App supplied with it and ‘fix’ the 2.4ghz WiFi channel to either 1, 6 or 11 - these are the main (non-overlapping WiFi channels)… you could also set the channel width to 20MHz if you see that option.

Then in the Sonos App goto Settings/System/Network and change the SonosNet channel so it is at least 5 channels away from your chosen 2.4ghz WiFi channel.

… and that’s it.

All the best from Ken (aged 5-1/2 yrs ha ha )

If your struggling to change your routers WiFi channel, then maybe just try other SonosNet channels in the Sonos App, but give things a good 20 minutes, or so, to settle before trying the next channel and just see which works best. Keeping the Boost well-away from other wireless products is a good thing too.

Thanks so much for the help Ken!  I will certainly give this a try.

Turned up here with exactly the same issue, so I’ll try the same tomorrow and report back.