Product page scroll animation


I’m trying to get a certain scroll animation to work on my product page but I’ve been unable to achieve it so far unfortunately.

Basically what I’m looking for is an animation exactly like this:

In short: The product should scroll down with the bar and settle in the section under it, when scrolling back up it should go back again.

I’ve sort-of got it to work as you can see on my published share link, however it’s not quite perfect.

Any help would be greatly appreciated.

Many thanks in advance,

Here is my public share link: