Sometimes when updates are done, the restart process can result in duplicate ip addresses being issued. This can make speakers inaccessible. A fix for this is to do a restart of all your devices and your router, and then setting fixed/allocated ip addresses for Sonos devices. Your router manual should tell you how, or post your router make/model and someone may be able to guide you through it. 

Please save factory resetting for a last resort, after calling Sonos support.

It rarely solves an issue, it may hide it for a few days, it makes a lot of extra work for you and it wipes all support data Sonos could use to help you.

I also recommend assigining static/reserved IP addresses, then power down all, power up router and Controller then Sonos devices.

Umm . . . Thanks, Stanley_4!  Problem is I’m a “newbie” at Sonos and its behaviors.  And, my Windows 11, isn’t all that stable (but that’s a whole ‘nother thread on Microsoft.) 

Needless to say, that’s a good idea.  I pray I can use desktop to assign these.  I sure hope what happened today won’t happen again.  I definitely look into assigning addresses and use your method.  It sounds a lot less hellacious than what I went through this morning!  Thanks!

You need to change settings on your router, as I said in my earlier reply, but you should be able to access this from your pc. If you’re unsure how, tell as your router make/model and we might be able to help (as already said).

IP addresses are assigned from your router, usually a web page called DHCP Settings or the like. It should have instructions linked in there.