8 weeks is plenty long enough that your new box has potentially been deactivated through non-use. To rectify that, is a call to VM with the box S/N handy.
Although I'm not seeing clear confirmation in your post, that this extra room has the necessary coax & internet connections present for any VM TV box to work. The internet can be WiFi or Ethernet (via your homehub), but the coax is a physical connection that's either inplace or not.
If everything is inplace, then you most likely just have an activation issue that a call to VM can rectify. If there's no coax connection point in this second room, then I'm afraid you're stuck until such time as VM are allowing multiroom installations. Additional room installs have been self-serve only since a while now, with no firm news on when this may change.
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