archive page messed up

I know I’m doing something wrong but I don’t know what it is. The archive page here at https://www.levjoy.com/bronxblogproject/category/student-posts/

is working fine, but on another archive page,

https://www.levjoy.com/bronxblogproject/category/videocasts/

the template is broken. I don’t know why this is. Any ideas?