Question:
I made a menu in the desktopversion within a lightbox which works fine. In the mobile version I only see the box (background) but not the menu. Neither in the editor nor on the phone. Any Idea?
Product:
Wix Studio Editor
What are you trying to achieve:
A solution 
What have you already tried:
I tried different sizes of text and lightbox.
Thx!
Have you explored the option of using a hamburger menu? It has a lot of the functionality out of the box, without the need to use a lightbox - Studio Editor: Using Hamburger Menus | Help Center | Wix.com
That being said, are you able to share a screenshot of the editor with the lightbox open on the mobile breakpoint? Will help to see what might be happening 
I am having the same issue and tried a Hamburger, but the menu doesn’t show up at all on Mobile. I cannot even locate it, even in the list of hidden elements. At least with the lightbox, the button linked to the lightbox shows up and other content inside the lightbox (an image) appears. So the issue at least seems specific to a menu. Help?
After a lot of digging, I think I found the reason why this is not working. Wix does not yet support showing advanced menus in mobile: Request: Creating Multiple Menus for Your Mobile-Friendly Site | Help Center | Wix.com
