Hi @CharlotteFairbairn
The advice is very similar to that given above. It looks to me like Bathroom 2 isn’t the best choice of Group Coordinator for your system - in fact, it looks like it might be the worst as it looks physically isolated from the rest of the system. Please test playback with either Dining Room or Living Room being the first room selected in the group (disband the group, select one of the rooms mentioned, then group to it).
Living Room looks like it might be particularly close to the mesh WiFi node - it may help to move the node away from the other devices nearby, 1m minimum.
Finally, you’ll probably get better results by permanently wiring one Sonos product - except for the Sub, Kitchen 2 or Bathroom 2 - to the main mesh WiFi node via ethernet, if you can. If you wire the Arc, make sure to move the mesh node away as previously mentioned.
I hope this helps.