Create Disappearing Image on Scroll Effect

Hi, I hope you are having a good day so far.
I am simply trying to create the effect of a visible logo image in the center of the hero banner, then immediately scroll is activated this disappears only to be replaced by a smaller sticky logo at the top of the page., like this www.fraserpt.com
The problem I am having is when I use
Element Trigger
While scrolling in view
Add Scroll Action Opacity 100%
Add Scroll Action Opacity 0%
When I play live preview it works, but won’t work when I save it.
6 hours later I need HELP!
If anyone is able to shed some light on how I can do this I would be most grateful.
Best and healthy wishes
Fraser