Understanding attic transition from fiberglass to no insulation + house wrap

I’m trying to make sense of what is happening in the attic over my garage. The knee wall transitions from fiberglass batts to empty bays with what looks like house wrap sticking out of the side. An infrared camera shows little temperature difference between the insulated and (seemingly) uninsulated area, which makes me wonder whether there might be insulation hidden under the sheathing. This transition occurs within a single room, a bedroom. Any thoughts on how to further investigate what’s going on there?
In any case, would it be safe to insulate these bays with fiberglass and a sheet of foam board on top, or would this create a dreaded vapor barrier sandwich? If that would be a problem, what should I do instead?
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