Welcome to the Community!
That's definitely a peculiar issue! Sounds like a potential zoom or ooverscan issue, but it's odd that it's only impacting the menu. It's possible that there may be an issue from a firmware update that's only impacting that box. You may need to have the set top box exchanged to resolve it. I would recommend reaching out to support at your convenience to have a technician visit.
Definitely let us know how it all works out!