how can i fix this shadow ghosting effect?

What is this ghostly shadow? How can I remove it?

I found the cause of the rightward shift due to ‘AspectRatio’, but why does this happen? That is the first question. The second question is, a trailing effect still remains regardless of any AA.

This is the video after I disabled AspectRatio. You can see that shadow ghosting is present even with AA None anti-aliasing. But I need AspectRatio and need to eliminate this shadow play / shadow trailing.