ScrollTrigger in overflow container

[MouleAGauffre]

Hello everyone ! 

I am having his issue of needing to animate elements that are within an overflow container. As you can see here by default, it seems GSAP doesn't pick up the positions of the container being scrolled thus the scrolltrigger never gets activated. 

The behaviour I'm looking after is that when the first blue square hits the top, the animation gets triggered. Right now, I need to scroll all the way down and then somehow scrolling some more gets the markers moving and triggers the animation (I'm thinking this is due to the pinspacer). 

If you'd have any thought on how to get around this/ info on the inner workings,  it would be highly appreciated. 

Thanks a lot for any help you can provide

See the Pen vYvVmLa by Typhainethegales (@Typhainethegales) on CodePen

[MouleAGauffre]

Actually I just found the answer to my problem for anyone interested I just needed to specify that the scroller to be the container with the overflow behaviour

[Boba]

@MouleAGauffre how do you set  the scroller to be the container with the overflow behaviour?

[GreenSock]

Just check the docs for the scroller property. 

scroller: "#your-scroller"