Whilst formally within accepted limits, your downstream SNR looks a bit borderline to me, although whether that's material I can't say - as power levels vary over time they could be worse and therefore out of limits at times. When they pick up this post the forum staff can take a more thorough look at hub data, and they are friendly, helpful and do their best, unlike the offshore telephone mumblers. Give that a day or two for a response, see what they say. They may identify a fault, get a technician booked who'll fix it first visit, and then everybody is happy.
Regarding reverting the upgrade, much depends on the forum staff response - choose wisely. Do you really need 1 Gbps? Only you can answer that question, and if the answer is yes then you need to stick with it and force VM to get things working properly, potentially by repeating tests to get at least one instance of speeds below the minimum guarantee on three consecutive days, and invoking the VM minimum speed guarantee. Sometimes a single tech visit is enough to sort these out, sometimes the problem is elusive and requires repeated visits and considerable persistence on the part of customers.
If the answer to do you need it is "no, I just thought it was a nice idea" then (subject to any reply by staff here) cancel now, and don't be persuaded by any garbage from the agent when you phone to downgrade like "it takes a few days to settle down" or offers to send a technician out that take you outside the 14 days. You usually won't have to return the Hub 4 in that situation.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks