Scatter + Motion Blur Issue

[jan_wielert]

Hello guys, as you can seee in the picture, I get weird dark strikes/ clouds when rendering scattered objects(trees) with motion blur. I get this with trees from chaos cosmos as well as with my own trees.
Can you tell me, what's the issue here? Merci!

[jan_wielert]

...and is there an option to convert scatter to instances? Maybe this will solve the problem.