Link to full size image not working

I have several galleries on this site and they are affected in the same way – when I click on a thumbnail in a gallery, expecting a full size image to pop up, nothing happens.

The galleries are set up correctly, I think
Gallery settings

I have tried deactivating plugins one by one and can’t find a conflict.

Can you suggest a way to fix this?

Many thanks ??

• This topic was modified 3 years, 8 months ago by stevethefootycoach.

The page I need help with: [log in to see the link]