The site is password protected and not meant to be public. I am not allowed to post this site here as of now.
To describe the problem better:
The sticky header shows up normally when scrolling down, but as soon as the end of the first div is reached, the sticky header gets stuck there and does not move on when scrolling further down.
Different question: Is there a way to set the “start point” of the sticky header? Like a set height, at which the sticky header pops up?