Motion 4 issue

Hi all

Im working on some animations in Motion 4 but I seem to have stumbled across a problem that I cant seem to solve

I am attempting to have a playing card spinning on the screen and whilst I seem to have nailed the animation for this with both the front and back of the card spinning nicely together one problem that I seem to be having is that when the animation is played the two layers spinning together (as a group wiht a spin behaviour applied) seems to look like a really bad interlaced image with loads of horizontal lines instead of a smooth image

Could anybody suggest a reason why this may be happening and what could I do to get rid of this issue

Many thanks

Lee