Hi Daniele,
I managed to speak to tech support this morning and discovered what I was doing wrong. I installed in my lounge for the superior WiFi speed instead of installing in my basement in place of the old unit. WiFi in the house is no faster than it was unfortunately, despite a couple of decent routers (tp-link) at around 12Mbps as opposed to the 350-550Mbps from the new modem. Obviously the new super speed is nice but in my basement not much use.
Do you have a cost-effective solution to propose?