I suspect there is no fix. I suppose it MIGHT be other causes, but that BQM is a classic over-utilisation pattern - you see how it's very poor during normal waking hours, and then peachy from about half past midnight to 9 am? Shows that the network and your hub are working perfectly when there isn't too much traffic. Nothing you can do to improve matters, this is caused by there being more network traffic than VM's local equipment can handle. Data packets are queued for fractions of a second at the pinch point, which often causes no problems for measured speed or casual web browsing, but destroy latency for gaming or videocalls,
In some areas VM undertake work to rejig the local networks to balance loads and eliminate over-utilisation. But sometimes that's either not possible, or judged uneconomic if there's a need to spend money on more equipment. In these circumstances there is often a fault reference and a "fix date", but there's no way of knowing if that fix date is actually backed by an actual plan of action and programme of works. Quite often it seems not, and as the fix date approaches it is simply moved a month or two ahead. Your options:
1) Sit it out, and hope that VM do carry out improvement works (don't base any hope on promised fix or review dates).
2) Get yourself a new ISP. If you're in a fixed term contract you'll probably have to use the VM complaints process (and arbitration at CISAS if need be) to try and be released from contract without penalty.
