At mobiles the submenus are overlaid by the smart slider (you can see it with Edge using the Format Samsung or similar, or displaying the page on a mobile)
Also the content is not displayed under the Submenu.
Looking at the css with google (simulating a Mobile and looking at a submenu, here the content is correctly displayed under the submenu) I see that the Megamenu z-index is deactivated with the message:
The position static prevents z-index from having any effect, Selector:mega-menu-wrap-primary #mega-menu-primary > li.mega-menu-megamenu > ul.mega-sub-menu
The page I need help with: [log in to see the link]