Do you have Apple Homekit lurking somewhere?  That is usually the guilty party when this happens.  It has never yet turned out to be an issue with Sonos itself.

Not that I can see. I definitely never installed it. Our household is all PC and Android. Although, now that I think of it our son has an iPad and that it is where the problem began. Will see if Apple Homekit is maybe installed there. Thanks!

I checked the iPad and neither the "Home" or "Controller for Homekit" apps seem to be installed on the device. The Sonos App may have been on there at one point but I uninstalled it months ago...

I don’t believe the app being on the same device is relevant.  Something external to Sonos is doing this. 

iPads and iPhones come with Homekit installed by default, I think.  If it has ever been there, I still suspect it!

Interesting. I'll keep digging. It would definitely make sense as the iPad is where the problem began.

I am not an Apple man either.  But if you go to Settings, is there a ‘Home’ icon?

Sure enough Apple seems to have been the culprit! One of the last things I did after all the troubleshooting was remove all the members from my Google Home "household" without thinking it would change anything. The next day the speaker didn't rename itself and it hasn't happened since!!! I've added everyone back except the iPad user.

In terms of Home settings on the iPad I can see that there is definitely a category in Settings. You can toggle "Home" on or off but there don't appear to be many configuration settings to change except who you allow to access the TV or speakers. I suppose if you install the actual Home App you could do more.

@John B Thanks a ton for pointing me in the right direction!!! After all this I'm in no rush to try and get the iPad working with our Sonos. For another day or month... Maybe. Lol

Well. The Apple gremlin doesn't want to give up under any circumstances. Persistent pest. It's been several days of peace but today our Living Room has once again decided to rename itself to Living POO. Lol.

When I had delved into the iPad settings a few days back I toggled "Home" completely off in the iCloud settings and also toggled off "Use this iPad as Home Hub". I just re-checked and all those settings are still off. I now noticed some text that says to "edit or make changes to Home settings" install the Home App. So maybe I need to install the app to undo what was previously done. It makes me apprehensive to restore it but maybe the solution will lie within. Lol. What a journey!

What I do find odd is that the iPad is in use every day so why so many days later is the renaming happening... And so is there possibly another culprit at play. We shall see.