Thanks for sharing! seeing your character in motion when you PIE definitely looks like motion vector issue. When you are in editor, the motion vector looks fine with the VisualizeMotionVector as you see the arrows indirectating the direction where the pixels is going to on screen as they move.
But maybe they break for some reason on what I assume is your skeletal animation. Motion vector are directly computed by the vertex factory, and we have many different code path for the different kind of geometry you draw (static mesh, skeletal meshs, niagara particles…). Could you just double check when PIE with ~ to open the console and then type “show VisualizeMotionBlur”? This will show the motion vector while controling you character and here I strongly suspect the arrows on your character would look broken compared to the motion of your character on screen.
Thanks for pointing out at the motion blur disabled! Another project settings related to motion vector code path is “Velocity Pass” in the rendering project settings (or r.VelocityOutputPass cvar)