When creating a new menu for your own or editing an existing header’s menu, you’ll need to add a CSS class for the menu to work like a normal site menu, or it will only show list of menu links.
Setup menu in Elementor
1- Create a Section
2- Find and drag Navigation Menu to the section
3- Skip the title and select a menu
4- Go to Advanced tab
5- On CSS Classes insert nav as the CSS
6- Click Publish to update the menu