Checkout page scrolls underneath navigation

On the checkout page for the below site, I’m using the basic checkout form webflow sets up, but my navigation bar is “sticky” and fixed to the top… the checkout form somehow is scrolling underneath it… I’ve set padding on the section wrapper and doesn’t help.
There’s no other section that behaves like this !
The issue is that when you scroll, it cuts off the right side summary block.

Here is my site Read-Only:
(how to share your site Read-Only link)