The power levels in your Downstream Channels are far too high (Max 10dBmV) .
Have you checked the 'Check Service Status' at the top of the page ?
If nothing is showing try phoning 0800 561 0061, this will tell you of more local issues that may be affecting the area. Be aware that it isn't a manned line.
If nothing is showing on the status lines you will need an engineer to sort out the Downstream Power levels.
You can contact VM to report your problem using ...
Text service on 07533051809
150 from Virgin landline.
0345 454 1111 from any other UK phone.
The best time to call is weekdays 08:00 to get a UK agent, anything after 10:00 you must realise that you are quite likely to get through to an offshore agent that doesn't speak English as a first language.
Or you can wait on here for one of the VM Staff to pick up the thread but this may take a few days.
Thanks for posting on our community forums. Sorry to hear you're having issues with our internet services, we appreciate the frustration caused when things don't work correctly.
Looking remotely from our end with the details provided form you community profile we can indeed see there is a downstream power level issue that needs to be addressed as pointed out by our valued community member MikeRobbo .
Due to this I have booked an appointment for a technician to attend to get this looked at for you. You can check you appoint time by logging on to your online Virgin Media account here you can also cancel or re-schedule the appointment if it is not convenient.