Hub 5

Contact Virgin and get them to send you a Hub 5. They're much better than the woeful Hub 3/4s. The Hub 5s are WiFi 6, newer standard. They're actually pretty decent. Even if you end up using the Hub 5 as just a modem it will be superior, better chipset without the bufferbloat latency issues the Hub 3 suffers from.

I have the Hub 5x and while it doesn't have a modem only mode, adding my router to the DMZ on the Hub 5x and turning off the WiFi on my Hub 5x has not caused me any problems with NAT.

When I was with virgin on their gigabit package I got the hub 5, have you tried that? I live in a large 7 bed house and the coverage and speed was actually impressive.

What’s your router? I’ve found the Hub 5 to be an unbelievable step up from the 3

what do you need it for? assuming you're on sub 1gig connection. Or you'd get the hub5, which is usually enough. I have a old Unifi AP central in my house and it works solid, I get 300-400 pretty much on all wifi devices, anything I need bandwidth on is plugged in. Weirdly I get around 20mb odd about 20 meters away at the end of the garden

I’ve had nothing but problems with the 5x, like you I set up my ubiquiti DR in DMZ and turned off the WiFi on the 5x. It worked for about a week then the internet stopped working and turning out the 5x didn’t like its WiFi turned off. Couldn’t turn upnp on it either and simply refused to turn dhcp off on it. I managed to get a working solution with it eventually but I was told I could put the hub in modem mode when signing up which was a complete lie. You can actually put it in modem mode as it’s a hidden page on the router and some people claim they have had success with it but wouldn’t work for me.