Can you please post a screen shot of the system page within the Sonos App?

Thanks, Can you scroll down a bit and show me the devices that you have installed?

If you play music and then follow these tests and let us know which tests work:

1. Pick any Room that normally works and start music playing 

2. Select the Rooms tab and add another Room to the group.

3. Carry on with step 2, until all Rooms are grouped and confirm audio is output from all Rooms.

4. Now remove each Room one by one, untill your problem Room remains 

If after following these steps your problem remains, can you please follow the steps in this article and then retest the 5 steps above.

https://en.community.sonos.com/speakers-229128/tips-tricks-resolving-random-issues-impacting-sonos-devices-6845346

Thank you for these suggestions, but neither method worked for me. In the first method, the problem room always goes off whenever I ungroup the next to last zone, regardless of which zone I save to that point. I also checked in my router app and none of my devices are assigned the same IP address.

As I explained in my post, your router will not know about previously allocated IP addresses, so a look in your Router will not show any issue.