@David-TP 

The satellite Decos were connected via WiFi. I did eventually get it to work late yesterday with no idea why because I didn't do anything different to the other times that I tried to get it configured. That's the good news (I suppose) but the bad news is half the things that use my network wouldn't connect despite using the same SSID and password as before  (I have around 40 devices) without re-entering the login credentials. The worst aspect was the actual coverage of my network was worse using the mesh than it was just using the WiFi on my router which was disappointing to say the least for example my 2 music streamers went from having a good connection to a fair connection and one of them was less than 3m from a Deco and in the same room plus some outside cameras went offline and I couldn't get them to connect.

I've now boxed the units up and will be returning them to Amazon.