Fade Animation - strange shadows

[Bristolman]

Hello,

I have Keyshot 8 Pro and some problems with fade effect in animations. When fading from 100% to 0% there is weird shadow which suddendly dissapairs in last stage of the effect. Is there any chance to turn the shadow off completely only for this particular effect or even part in assembly? I wanna keep rest of the shadows but not that problematic one. I have tried different lighting scenes: Product, Basic. That strange flick is always there. Please see the video attached. Any help will be highly appreciated.

[Öner]

it's weird, i use KS6 and i use the fade effect too much in the all kind of animations, and i have never seed before like that.  maybe you have too much surface on the same layer; could you please check it.  also a black contour line appears in the end of the effect.   

[Bristolman]

Thanks for suggestion. I have eliminated issue (partially) by instead of fading to 0%, i have set it to 1%. There is no weird flicks anymore (at least on the preview) and rendering is going since Friday. I'll check check your suggestion once finished in about day or two