There are no known issues where the boxes can't connect to either frequency so I can only recommend a pin hole reset at the moment because there could be something with the hub settings that's causing the V6 to have difficulty connecting. Once this has been done try to connect the V6 to the 5GHz network before any other device.
I'd also recommend the step that Louise_F has mentioned regarding connecting to the Network.
You can do this by going to Home - Help & Settings - Network - Connect to the Virgin Media Network Now.
Just had a new V6 box and it won't connect to my 5GHz wifi. It sees the SSID but refuses to connect despite entering the right password. I have no problems with other devices connecting at 5GHz (e.g my laptop / ipad). There is something wrong with the V6 box! Not impressed!
I've had my V6 Box connected to the 2.4ghz setting for years, and it works absolutely fine, if yours is working on the 2.4ghz setting then just stick to that, I'm getting speeds of 100 mbps on 2.4ghz which handles everything thrown at it.
What Hub is it ? If a Hub3 and you HAVEN'T renamed the SSID's of the two bands so they are separated and selectable it may not do so if it determines that the 2.4 band is "better" - particularly if the V6 is in a distant room from the Hub. Have you tried renaming the SSID's - if you have the Hub3 of course?
-------------------- John --------------------
My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.
It's a Netgear R6250 router configured as a wireless access point which I use to cover the downstairs area, as my Superhub 3 is in remote rear upstairs location. There's nothing wrong with this device as I mentioned that other devices can connect perfectly well on the 5 GHz frequency. All my SSIDs are different, and it was only yesterday that we switched on the V6 box for the first time. At 2.4Ghz, I get 144 Meg connection, but as more of family use devices, it will affect it?
I have up to 13 devices online at times including my son gaming in UHD without any problems being caused to the 2.4ghz my V6 Box in fact I've never had an issue at all with any of my V6 Box on 2.4ghz, it's better in my view than 5ghz, I'm getting 100% on 2.4ghz but only about 65% on 5ghz, I honestly can't see why you are worried if it's working fine why are you trying to fix it.?