gallery pages tries to load all images when visit the page

i setup a page with all gallaries on that page, when I visit the page, I noticed the page is try to load all images of every gallery, I have almost thousand images and it takes extremely long time in the case. pls see the link below (I have removed some images, otherwise, the page is not usable, link below still can see issues)

https://www.silongedu.com/summer-camp/

this does not make sense at all. Do I miss something? Could you pls advise how to fix it?

million thanks
Felix

https://www.ads-software.com/plugins/foogallery-owl-carousel-template/