Often powering down all Sonos, a router reboot and powering them back up will get past this kind of thing.

If it fixes the issue you should assign static/reserved IP addresses to all Sonos from your router’s DHCP settings page. Usually just a few clicks.

Thank you - oddly, the overnight update seemed to work. I pushed the update from an updated app on my iPhone and it failed. Not sure, but I woke up this morning and all of the items - besides the ones I unplugged in the error message got updated.