Click through from an attachment page

I am having trouble getting attachment pages to click through to another image.

I have managed it here https://www.hhct.co.uk/a. Bear with me: click on the link then on an image, then click again on the image, which takes you to the attachment page, and then click once more – and it takes you through to the next church. But I can only get it to work for the A churches. https://www.hhct.co.uk/o doesn’t work, as you’ll see. It doesn’t feed on to the next church page. What am I doing wrong? It’s driving me to distraction.

I am using the Academica theme if that’s important.