Motion Blur on looping Animation

Hi,
everytime i create an animation for some machinery in my project i do so with a looping motion like in this video:
www.messestand-online.de/UE4/loop.mp4

And as you can see on second 14 there occurs some kind of motionblur at the end of each animation cyle:

Of course the mesh has moved 30° and i think the engine is trying to smooth something out but in this and many other cases the normals of the mesh are identicale to the ones from the startposition… so my question is if there is any way to disable this?! I already disabled motion blur in post process but that doesnt seem to affect this one :frowning:

i would be glad if someone already ran into this one and has a solution for me :smiley:

I would check the PerBoneMotionBlur option.