I want to serve all of my website pages over https, but currently my htaccess only serves the homepage over https.

This is the code I have in my htaccess file:

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteCond %{HTTPS} !on
  RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</IfModule>

If you go to the following page it is served still over http: http://www.coerll.utexas.edu/spintx/video/1506

But the homepage is served over https: http://www.coerll.utexas.edu/spintx/

What am I doing wrong?