In Latex pdf export (C-c C-e l o) $m$ renders correctly as italics m but in HTML export (C-c C-e h o) it renders as Roman m.

Reverse slash Latex formulas like $\mathbb{N}$ render fine in both Latex and HTML.

How can I fix this so that $m$ renders as m in HTML too?

I use this header for both exports:

#+SETUPFILE: ~/.emacs.d/org-templates/level-2.org
#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="http://cavendish-deneyi.com/css/worg-classic-new.css"/>