How to remove a 1-second appearance of scrollbars from a div

Question

Hi,

site is www.onlinefilmbox.com

When it loads, you can see that for a second, horizontal and vertical bars appear on the carousel in the center.

They appear for a second and then gone.

But I wonder - can I remove this short appearance?

I tried "overflow: hidden" and "overflow-x: hidden" + "overflow-y: hidden" and both don't change anything.

any idea?