I was messing about in the editor and when getting in and out of the hunter, i noticed that sometimes my rear camera (on the dashboard), my mirrors and the turret's PIP screen would go black, this was occasional and after getting back into the vehicle it could be fixed.
Screenshot #1: Shows the rear camera's screen black
Screenshot #2: Shows the mirror being black (in the same sitting as screenshot #1)
Screenshot #3: Shows the mirrors and rear-camera working again after getting back in
Screenshot #4: Shows what the PIP in screenshot #5 is supposed to show and proves that the in-sight-view is working
Screenshot #5: PIP on turret camera not working, while mirrors from driver's view are (not sure if this actually is PIP if you're sitting in turret seat, just showed a ground texture, but i was on a slope so it could have been correct)