I have Sonos throughout the house, including an Amp and surrounds in the living room, Fives upstairs - and Play:1s and One SLs downstairs, across multiple rooms.
Always worked perfectly until a couple of months ago. I’ve switched to Qobuz, so presumably data throughput is higher than when everything was Spotify, Mixcloud, Bandcamp, etc. However - that doesn’t really explain the problem as far as I can tell.
When I join the Kitchen speakers to the Veranda (both stereo pairs), I get massive dropouts. The Veranda is the closest room in the house to the kitchen. Individually, the zones play music absolutely fine. Different albums on Qobuz at the same time in every room, no problem. Same album at the same time when grouped, if Kitchen and Veranda are both in the mix, always results in terrible dropouts.
I bought a Boost in the hopes that might help. We’re on a Google mesh wifi setup, which I understand is problematic unless you connect the Boost directly into the main hub, which I’ve done. I’ve also connected the Kitchen R speaker to the Boost by ethernet - and disabled wifi on that speaker in case that was an issue.
Honestly I have tried everything I can think of including fixed IP addresses for individual Sonos speakers and replacing the speakers themselves with the newer ones I bought to install in an upstairs bedroom when the renovations are done. Keep coming back to the same problem. I’ve tried having the Veranda as the main speakers, and the Kitchen as the main speakers. Makes no difference.
The only thing left I can think of is that I have IKEA Trådfri lightbulbs connected to a hub and controlled via wifi. There are a bunch of those in the kitchen, reasonably near to the Sonos speakers. Could that possibly be a thing?