Are these players included in a voice control scheme? As I recall, Alexa can sometimes revert a player to a former name. If so, you’d need to change the name in Alexa.

Apple’s HomeKit can rename rooms, certainly. 

Mmm I have both.  Just moved to a eero Mesh service and so far they have not changed identity.

This is still happening,  may take a day ,may take 5days.

Diagnostic 240391277

Driving me mad.

Have you tried removing Alexa and Homekit?

Yep. Done but still it changes. I can’t find any trend either. 

Hi @bockersjv 

The only documented way of this happening is due to Apple HomeKit.

I recommend checking every Apple device for HomeKit being installed and the Dining Room having been added to it. A Sonos room name change simply will not stick if the room is included in HomeKit, unless the name is changed in HomeKit.

I hope this helps.

In past cases, whenever anyone has come back saying they have eliminated Homekit, it still turned out to be Homekit that was to blame, lurking in some vestigial form on a forgotten device.

Just saw this and checked my iPad.

Thanks John B and Corry P.  Yes there was a dining room still lurking there. Have removed it and checked that it has not reappeared on my phone. 
let’s hope this solves it. 
 

An internet search “site:sonos.com rename” has the Sonos knowledgebase article as the #1 hit:

https://support.sonos.com/en-us/article/sonos-room-names-changing-on-their-own