Hello, I am having the exact same issues as the poster here, no different at all. I've seen Virgin media users all over the place reporting the same issues. Please can I have them resolved, I have port forwarded and enabled UPNP and tried all the common solutions, my connection beyond this issue is also dire.
Thanks for telling us a little more about your setup. I suspect the switch and powerline may be causing the strict NAT so I'd suggest trying a direct ethernet connection to the hub in modem mode to rule this out. Here's a link on how to put the hub into modem mode.
More than just myself use the hub, so I can't leave it in that mode, which as you haven't told me how to test it seems to be your solution? I really hope not as its not a solution.
So what I really need to know, is why, no matter what I do, what setup I use, the connection is strict. It suggests virgin are blocking ports that these games need but I could easily be wrong. All I want to do, is stop my NAT being strict and I've done everything that needs doing for that on my end, so please look into it on your end. (and yes, I tried plugging it in directly which is a pain as I'm in a different part of the house, but it didn't achieve any different results)