Trouble shooting a layout error

So I have a header that is identical on every page of my site. The intent is for it to be fixed to the same spot at the top of the screen and for the content to disappear under it as you scroll. On some pages this is successful, however when I copy and paste to other pages it sometimes doesn’t scroll how I want, it instead scrolls over the header. I am unsure why this is occurring as the settings for the header are copy and pasted. Any ideas? see pages “2d work” and “3d work” to view the disparities.

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

Hi Manon!

Put a z-index on the heading section to make it go over the others sections!

The z-index CSS property sets the z-order of a positioned element and its descendants or flex items. Overlapping elements with a larger z-index cover those with a smaller one. So an element with z-index 10 would go over one with z-index 9.