share not clickable on divi gallery?

Using the Divi plugin and the built-in gallery, when I click an image it opens in lightbox, and then the sharing buttons are above the image (instead of on the image) — so when I try to click them, I have to move my mouse off of the image… and then the button disappear.
How can I get the buttons to appear lower?

Also, I bought the Pro version, and I can see I can set a class of image to include (or exclude) but I could not find any instructions… where do I set the class????