So the internet connection is working, but if the box works in a different location that suggests a problem with your internal coax cabling that carries TV signals to the other room.
Have you made any changes to your account recently, are you definitely paying for a multiroom subscription? I'd expect the same box to fail regardless of connection (rather than the connection-point fail regardless of box) but it's something else to rule out.
Best you can check is that all the obvious connections are finger-tight, otherwise you'll need to call in and report your service fault. How far VM can troubleshoot internal cabling in the current climate, I'm not sure. But there's one way to find out.
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