We have a site (behind a firewall unfortunately) in which MathJax works in the browser, but if you press Ctrl-P to print, the MathJax doesn’t render and you just see the raw MathJax markup.

Example content: (although you don’t seem to have MathJax enabled in the meta.discourse.com forum)

$\sqrt{16}$ score and $e^{j\pi} + 2^3$ years ago, our forefathers did something or other.

$$

x^2 + y^2 = z^2

$$

Well, darnit.