I have a long mobile menu on my website, it works fine, but not with the sticky header script. You can see it, if you delete or /comment/ the sticky header script Codepen

I tried to copy all necessary styles and scripts, but without logo and icons, just imagine that burger svg is changing to 'X' when it's opened. It's only for mobiles, so I wrote max-width 485px, originally it was @media.

When submenu items are opened, I can't scroll the window down. The 'overflow-hidden' is only for x, for y it's auto. I tried to add

jQuery('header').removeClass('sticky');

there, inside

jQuery('.burger-toggle-item span.fa-burger').on('click', function() {
  jQuery(this).toggleClass('fa-burger fa-close');
  jQuery('.burger-menu-wrapper').slideToggle();
});

Tried to change position absolute to fixed. How to make that menu and sticky header friendly to each other?