Motion Blur artifacts at Game Start

Hi,
so when i start the game theses artifacts are appearing, and if i not move the mouse they will stay…
However i can get rid of them if i disable the MAX option in the Motion Blur settings. (max distortion caused by motion blur, in percent of the screen width). Right now i have this value on 10 and i need this exact value. Otherwise i get unwanted distortion artifacts in my weapon reload animation…
What can i do to get rid of these at starting the level?