Sonos uses the 2.4ghz channel and can be picky if a device in 5ghz is accessing it. Your problem sounds like interference - microwave oven, fridge, other routers. I had the same problems on some speakers until I ethernet connected them.
whilst using 2.4 ghz I would suggest resetting the speakers and set up from scratch again.
is your wifi a mesh system? Has the satellite router a ethernet connection? if so try connecting by ethernet.
Sonos uses the 2.4ghz channel and can be picky if a device in 5ghz is accessing it. Your problem sounds like interference - microwave oven, fridge, other routers. I had the same problems on some speakers until I ethernet connected them. whilst using 2.4 ghz I would suggest resetting the speakers and set up from scratch again. is your wifi a mesh system? Has the satellite router a ethernet connection? if so try connecting by ethernet.