More than one version of WDMyCloud

I am using the WDMyCloud as an NAS with both music and pictures stored on it. I use the music with a Sonos system and the device was named as WDMyCloud2. I did a factory restore (think its the middle one where you lose all your data - but not a problem as it was all stored elsewhere and I could load it back on. This was done because I was showing the pictures on a Pix-Star photo frame and I kept getting an ‘Impossible to connect to UPnP/DNLA source’ across some of the pictures and the frame picture would freeze. Now I have restored the device that seems to have been resolved (fingers crossed). I named the device just WDMYCloud (omitting the 2) on restore but every time I go to play a track on the Sonos it says it cannot find the track and refers to the WDMyCloud2 device. It shows the device named as WDMyCloud in the Dashboard, but when I sign into the other access page (not sure what its called but has ‘search for devices in my network’ and ‘show previously connected devices’ it shows a WDMycloud but when I click on ‘connect’ I get the ‘sit back and wait while we connect to the device’ but this comes up with a sign in screen which wont let you sign in?? It does not allow you to sign in to the ‘name’ space.
So I use the 'Connect to devices with WDMyCloud.com login. Which I do and then get a number of devices shown including one of the WD MyCloud2 and 3 WDMyClouds shown. So iy appears that the WD MyCloud2 is still lurking about somewhere (or at least the name) and the Sonos system is trying to use it as a music source. Howver, signing in to any of the devices this way always fails!
How do i get rid of this version of the device?
Sorry a bit long winded but any help would be appreciated.
I pointed the Sonos app at the music tracks saved on the main PC and it works fine but not what i want.