Hi Atown25,
This sounds like one of the older TIVO boxes. If it is there should be three green lights on the front left of your box. The first light is the power light and should always be on.
The middle light, next to a heart symbol is the heartbeat light which indicates the internet connection. If it's flashing then that means the internet connection has dropped and that's causing the services you are watching to drop out.
When that happens you can force a manual reconnection by going to Home > Help & Settings > Settings > Network > Connect to Virgin Media Services now at the bottom of the screen, waiting a while and repeating your check of the timestamp in the top-left.
You can ignore the port configuration test, it honestly doesn't do anything.
Since it keeps recurring, and you've tested all wiring etc you should report this to the TV Faults Team on 150 from a Virgin landline, or 0345 454 1111, options 1,1 and 2 (Faults) but best to call at 8am to avoid call queues, or around tea time.
When phoning, ignore the automated response asking you to press 1 for the link to online support. If you don't press any buttons then you should be placed into a queue and an agent should pick up the phone and resolve the problem. They might offer to send signals to the box, but that won't rectify the issue.
They might also offer to send a new set top box.That might work, but it's very likely the signal and so probably won't help. Insist on an engineer visit so they can check the cabling internal and external and fine tune the signals. The engineer will carry a spare set top box if he decides one is needed.
You could also try the text messaging service. Just send a text with a description of TV Faults to 07533 051809. Your message will go into a queue and a representative will respond to you as soon as possible. It may take a few days.
Dave
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali