[Plugin: Shadowbox JS] Shadowbox no longer working on my site

I had Shadowbox working before, but now I can’t get it working. When you click on the image, it will just open up the image normally. I can get other lightbox plugins to work, but I like this one the best.

Here’s a page that uses the plugin: https://www.vineandgrain.com/savings-tour/how-much-can-we-save-you/

I’ve looked at several other posts, but none of the solutions have worked for me. Can anyone help?