404 redirect when attemptimg to open full k2

On my site, I am using a 3rd party K2 gallery that allows you to open up an image gallery or the actual article. The image gallery works, however when I try to open up the specific article page, I get a 404 error.

I have tried using another template and the link to the k2 item works. Am I missing something with Onepage? Is there a way to display content in the template settings? Any help would be greatly appreciated.

I created this “hidden” page so you can see the issue.