We have recently upgraded to a HUB 3 and the landline connector was not supplied. We bought one based on previous forum answers (RJ11 plug to BT socket adapter) however this has not worked. i can confirm it is in the correct port.
Can you confirm the correct connector and also confirm if there are any settings that need switching on by Virgin for this to work.
At the moment we aren't able to set up accounts to allow the landline to be used via the Hub. We are at the moment in the process of migrating all of our accounts with a landline to be used via the Hub.
As you can imagine this is quite a large task but as soon as we're ready to make the change in your area we will let you know via letter or email.