If your BQM has that shape persistently, then the most probable cause is over-utilisation (network congestion) caused by VM selling more contracts than the local network has capacity to support. In addition the BQM looks to me somewhat "noisy", which can often be improved a bit, but fixing the noise WON'T solve the congestion or improve the impact on your internet. Further, the poor wifi performance is a feature of VM hubs, for which the only reliable solution is to place the hub in modem mode and spend around a hundred quid or more on a wifi mesh system; That will magically cure wireless problems, but again it won't alter the network congestion problem. Read this to see how VM respond to over-utilisation, and take note of the customer BQMs that are posted. A further search shows that the same or similar over-utilisation faults existed in that postcode through 2015, 2017 and 2018. And this shows that the unfortunate residents of that area are not alone.
Nothing you can do to improve matters. In some areas VM do indeed undertake work to rejig the local networks to balance loads and eliminate over-utilisation, and they spend millions each year improving capacity problems. But sometimes/often that's either not possible, or judged uneconomic if there's a need to spend money on more equipment. And sadly VM won't ever admit the truth, so even where there is a fault reference and a "fix date", but there's no way of knowing if that 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. Note that the staff here can only see a fault reference and the current fix date, we don't believe they have any visibility of whether there's an intention to fix the problem, so don't be too harsh on them, this is a company failing that rests with senior management. Your options:
1) Sit it out, and hope that VM do carry out improvement works. There's little or nothing you can do to force VM to upgrade the network, nor to be honest about the outlook. A very, very few customers have pushed VM into fixing over-utilisation that appearances suggest the company otherwise would not have, but that still takes the better part of a year, needs to become a near-obsession for the customer, and has significant costs to the customer in terms of ongoing stress.
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 almost certainly escalate for arbitration at CISAS ) to be released from contract without penalty. If you need to do this, the grounds of your complaint is the poor performance, and your request fro release from contract without penalty is twofold: First the Consumer Rights Act 2015 that requires any consumer service to be provided with "reasonable skill and care", and second, the Ofcom Fairness Commitments, that states "Customers’ services work as promised, reliably over time. If things go wrong providers give a prompt response to fix problems and take appropriate action to help their customers, which may include providing compensation where relevant. If providers can’t fix problems with core services they have promised to deliver within a reasonable period, customers can walk away from their contract with no penalty."
The ball is now in VM's court. If they can identify a fault on your line, fix it and remove all of that peak time latency, then you get the outcome you want, and my prognostications of doom will be proven worthless. I'm sure you'd be happy with that, and so would I. If on the other hand there's mention of an over-utilisation fault, chances are nothing will be done, any promises of fix dates will pass without change, and you need to review your options with other ISPs.
