Seem to be having a lot of issues with my Broadband recently. It's extremely slow at times and very intermittent. quite often cutting off completely. running a speed test just now showed 3Mbps with possibly a lot of packet loss. The issue has been going on for months but we had several router replacements which seemed to resolve the issue temporarily for some reason. Most likely our line is quite unstable and as we had older routers previously is would cause them to reboot. This new one seems to not completely reboot but the internet does cut off quite often. I'm also not connected wirelessly just so you know. It's definitely an issue with the line I'd say.
The upstream power levels posted are above the maximum recommended level of 51 which could well cause disconnections.
This will need a technician to visit and sort out the power levels. You can call VM and try to book a visit or wait for the VM staff to get to this thread and they can help you book a visit.
Disclaimer - I don't work for Virgin Media. I'm just another VM user trying to help out so my answers may be wrong If my answer solves your problem please mark it as helpful as it may help others My setup: Vivid 200 Optical fibre with Superhub 2 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.