Printing Not Working Correctly

So I created a javascript trigger to print a certificate (the last slide), using window.print(); When testing this feature out locally after publishing, it prints whatever is on the last slide. When the published version is placed onto our website, it still prints, but only prints the header and footer of the page.

I was wondering if there are any variables to consider that would change the reason as to why the printing is behaving differently locally as opposed to online.

Would printing locally via the html5 output vary the results, instead of printing anything that isn't html5?