Images appearing twice

So I set up a gallery in a post using shortcode. When I click on an image, two overlays open. One displays the clicked image with close button and the other opens below it and displays a slideshow. When I click right arrow, things will flash, but nothing will change. Clicking once on the overlay closes the top layer and you can see image has changed to next on the slideshow below. Why does this happen and how can I get rid of it?

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