I see you have Sonos devices and the screenshot shows you are grouping zones.
Are you grouping all your Sonos devices?
Are they on WiFi? If so, are they connected to various Eero mesh nodes? If so, are the mesh nodes connected together with ethernet for backhaul, or are they doing this with WiFi?
Thanks for your message. This error typically happens when something else tries to play to the zone (or one of the zones in the group). Is there anyone or anything else attempting to play to one of the devices while you have playback active? If you play to each of the zones when they are not grouped, does one stop playing while the others work as expected?