Max Mega Menu and GP Sticky problem

Hi there,

I'm using Max Mega Menu and sticky menu from Generatepress but I've the following problem:

* When I'm scrolling up from the bottom the menu appears
* When I'm almost at the top the menuitems of the megamenu slowly appear from the top of the menu while they're also displayed at the normal position.
* Result is a double menu for the last scroll-up...
* Hope I make myself clear, I've also attached a screenshot to clearify.

* Hope there's some css to fix it :-)

Thx!
Marcel Mooij