Hope this isn't really dumb but: I've got dark blue intrusion box lines on my live camera display. I can't find any setting to make these lines disappear.
Your interface may have things changed around depending on functions your NVR has.
From the menu, find 'display'. This may likely be on the next page (circles at the bottom to change pages).
and 'IVS rule' is the button to uncheck.
This will make the NVR's screen not show IVS rules. Including boxes around vehicles/people/faces.