Fixing Hidden Dropdown/Mobile Navigation Menus

Sometimes, when you create a navigation menu with a dropdown or mobile menu, the dropdown will be hidden behind the section below it like this:

This is due to the CSS z-index value on the row of the navigation compared to the z-index value on the row below it. To fix this, go to the row settings > Advanced > Z-Index, and increase the value, making sure that it is higher than the row underneath it.