When going from a region render (set in the 3ds max common tab) back to a view render, vray will only render the previous region. The workaround I do is to set the region boundaries to the full view and then it will be fine again. Was present in 3.6 and just saw it happen in Next.
3ds max 2016
win10
vray 3.6 / Next
3ds max 2016
win10
vray 3.6 / Next
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