Quick update - you can actually achieve this without rolling back the installation, reset the network settings on the personal cloud using the pinhole in the back. This then appears and you can set...

@Alexandre. What a superbly detailed reply - really appreciate it. I'm going to desperately try and find a way to change the fixed IP on it withouth rolling back the S4 installation but thanks so...

Hi All, I'm really stumped on this one. I've just installed a Deco S4 mesh network at home (3 units) - I'm on Virgin and have switched the Virgin hub over to modem mode. Everything works seamlessly...