Lightbox function has suddenly stopped working

Hi there. I recently built a website for a client using Webflow (I’m not an expert by any means). The site is a simple showcase of his artwork. He has contacted me to say his images are no longer appearing. Has there been an update to the image lightbox function? The enlarged images have just stopped appearing! Example: Thomas Thesen's Character Development

Any help greatly appreciated!

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Maybe try remaking that part of the website and publishing it again, could help but I can’t think of anything.