Menu- Remove Scroll/Overlap Feature

I would like to disable how the menu scrolls.

Ideally I would like the menu to scroll normally & when it reaches the top, I’d like it to stick all the way down the page. Does this make sense?

I usually use the ubermenu sticky extension plugin but whenever I activate it, the menu doesn’t work.

Mainly though, I really need to get rid of that menu overlap when I scroll down the page.