Collections detail pages don't have headers

repo: https://github.com/fredzannarbor/fredzannarbor

Why aren’t the collections pages getting formatted properly?

e.g. https://fredzannarbor.github.io/fredzannarbor/books_in_print/uss-bunker-hill

Not respecting the layout – https://github.com/fredzannarbor/fredzannarbor/blob/gh-pages/_layouts/books_in_print.html. – showing the content only.

Looks fine to me… Perhaps you did not wait enough for GitHub Pages to build and deploy the site…?