Sticky - Issues on Mobile

Hi All,

I’m having some issues with STICKY on mobile - When scrolling - I want the SECOND section (black) to stick and the THIRD section (green) to pull over naturally.

It works fine on desktops and tablets
, but not on mobile for the first time; instead, the black section sticks, but the green section sides under rather than over (if that makes sense).

Does anyone have a fix or any tips, please?

Many thanks.

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