get_header not working on new pages

Hello, I’m working on a website that was setup by another developer. The main pages on the website are all setup using templates, and display perfectly well. What I need to do is setup a new page on the site. However when I duplicate a template, rename it and load it back to the server, the new page I created doesn’t properly pull in the header. The page does display with everything but the header. The only thing I’m changing in the code is the “Template Name: XXX”. Then creating a new page from that new template.