Note: If you have enabled Modem Mode on your Hub 3.0 you will need to use 192.168.100.1 instead.
Do not login but click on where it says "Check Router Stats" and then copy and post from the following 4 tabs, Downstream, Upstream, Configuration and Network logs and we can check your power level, also while you about that can you please go around and check that all connectors to VM equipment are hand tight. Also while doing this please check for any damage to cable, or un-terminated connection without either coax or a terminator.
I dont work for VirginMedia all opinions are my own. 39 years in IT.
The downstream power levels are just out of VM spec on most of the channels. The upstream is a tad warm, but should be OK if stable.
The logs are showing the connection dropping and re-registering with the CMTS which would look like the Hub rebooting.
You could give the coax a quick once over checking for obvious signs of damage and all connectors are hand tight, but you will probably need a tech visit if there is not a local area fault.
You will need to contact VM for resolution, either by waiting here about a week until a VM Forum Team Member picks up the thread, or give them a call on 150 from a VM line or 0345 454 1111 for a quicker response.