Expanded hamburger menu under other divs despite high z-index setting

Hi All,

Despite setting the z-index for both the header and the expanded hamburger menu to 1000, the expanded menu still appears BEHIND the div at the bottom of my slideshow:

https://preview.webflow.com/preview/andyz?preview=e1be5af1b221ed3b07e8e78fc798e028

Any help would be greatly appreciated. Thanks.


Here is my site Read-Only: