Slideshow Redirect Does Not Work After 1st Picture

We have activated slideshow redirect links. On our slideshow the first picture redirect properly. The second and subsequent photos redirect to “Page Not Found”. All pages are linking to the same URL. This happens on all slideshows on our sites. All pictures are supposed to link to: https://roundlakecamp.org/activities/science/
The first picture is fine. The second and subsequent pictures go to this link: https://roundlakecamp.org/activities/undefined which results in page not found

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