@larkim Answering my own question - the solution was to log onto the IP address of the individual unit and upgrade from there. Should have thought of that sooner!!

@Joseph-TP Thanks, but I'm a little confused as to what you mean? I've got the 1.7.0 beta installed on all my devices, for the benefit of the "connection preference" option which has solved issues I...

@David-TP Logged into the unit from work by port forwarding port 80 on the Deco unit, but when I select the .bin file and hit upgrade I get a spinny wheel for a few seconds the "Operation Successful"...

Not tried logging onto an individual unit, will give that a go tonight (I'm away from the LAN at the moment). They are all V2, they show as such on the web ui as "M4R(V2)" when listed on the page...

@ImtiazAli The 1.7.0 is a beta firmware which I've applied to my (UK) units to enable the connection "choice" preference. The issue is that I've now bought a fourth unit which should be able to be...

@Joseph-TP Thanks. I already use 8.8.8.8 but having read a little more it may relate to the fact that I am on the beta 1.7.0 firmware as I've now observed that others report this sort of behaviour.