EDIT: Fixed, all of these tests were done against static objects, not movable ones.
Wow I must be doing something wrong, I picked up 4.27 just to see if there was something jank with 5, but I can’t get the PreviousFrameShift to work at all.
Motion blur is enabled.
The debug view shows the material motion, but not the motion in the editor. Also, neither the material editor nor the viewpoint show the material blurring.