I was editing and this white space appeared over the nav bar on the home page, no idea what I did and after several edits I’m afraid restoing the site from a previous version won’t help.
You are using negative margin (-80) to position the navbar and it is less than the height of the navbar (-84) so you are seeing the gap.
If you just add that green background color to the navbar and on the interaction then you’ll not see it.
But the best solution would be to not use negative margin and just apply green background to it. If you think height of the hero section is little big then you can decrease the top padding on that. This way you won’t have to worry about the positioning.