Working from home I have taken a BT Cloud Voice VOIP phone which is ported through a BT Router normally and plugged it into my Virgin Hub. The phone works perfectly apart from the fact I can’t hear the other party. I have tried rebooting both hub and phone but nothing.BT recommend I disable the SIP-ALG setting which does not appear to be on the virgin hub.
Unfortunately what you have described is a classic symptom of SIP ALG getting in the way and needing to be disabled - the problem is that the VM hub simply has no means of doing that. The only real option would be to put the Hub in to modem mode and get your own router which has that facility instead.