I have the same problem as a previous poster who couldn't get their 3DS to connect to the internet when in a game. It's fine connecting to download updates etc and the game connects when connected on another network. It's only on my home virgin media connection that this is a problem.
The response from the forum team which seemed to solve the problem was the person getting a new hub 2ac. I'm copying the response in below. How can I get my problem resolved? I believe my hub is the original superhub. Many thanks.
Thanks for getting back to us. I note that you have a Super Hub, one of our earlier models - since then we've had Super Hub 2 and Super Hub 2ac with the Hub 3 being the most current.
Super Hub is somewhat restricted in terms of Wi-Fi in that it offers only the option of either the 2.4Ghz or the 5Ghz frequencies, not both simultaneously. I'm fairly certain that the 3DS only connects to the former so if you have the 5Ghz option selected this will explain why you can't connect.
I'm only guesstimating at this point as I have no idea how or in what way your DS's are failing to establish a connection.
But this seems like a good place to start. Plus your current tier of broadband service is really better served with a more up-to-date model. So I've ordered a replacement Hub for you (Hub 3 has a few firmware glitches atm so I've opted for the 2ac though you may get a Super Hub 2 depending on availability).
Here are the details:
The new Hub should arrive within the next few days.
The courier, Yodel, will leave contact details should re-delivery arrangements be needed.
A text will be sent (to the mobile number we have listed for you) the day prior to delivery advising of an ETA.
Full setup and activation instructions will be included.