[Plugin: GRAND FlAGallery] pop-up not compatible with my theme after recent upgrade

Great plugin, thank you!
But I recently upgrade the plugin then I found that something is wrong with the pop-up function of FLAgallery widget. It goes up to the top of the window and I can no longer turn it off by esc or clicking the background.

You can see it here : https://swotong.com/category/uncategorized/ (click the right bottom image then you’ll see)

It might be just my theme “mingle”, because it seems to work fine when I switch to other theme. Please give me a hand. Many thanks!

https://www.ads-software.com/extend/plugins/flash-album-gallery/