Sub Menu items disappear under Elementor pop-up

Support,

- I use a generatepress navigation menu where a few items have a sub-menu.
- I also use an Elementor popup with a small height that will position just under the main navigation menu.

My issue is that the sub-menu items disappear under the pop-up and are not vissible.
Is there a way to ensure that the sub-menu items will show above the pop-up?

If I am not mistaken I should specify a Z-index of the sub-menu that is higher than the Z-index of the Elementor pop-up. But I do not know if that is the correct solution and if so , how/where to specify that ?

Please advice, thanks Walter.