Sticky Navigation in Theme covers pop-up

I am liking your plugin so far. However I have come across a problem. I am using the Elegant Themes theme called Divi. It uses a sticky navigation. The gallery pop-ups pop under the sticky nav which means the top portion of the pop-up is not visible. Can the z-index or top-padding be adjusted in the free version? If not, can it be adjusted in the paid version? Or is there another work-around?

https://www.ads-software.com/plugins/portfolio-gallery/