xtypo button does not work in category descriptions

I have used xtypo for a long time on another joomla site and it has been very useful. Thank you for all your work. I've just installed it on my new Joomla 2.5.8 site (editor Tinymce) along with the new xtypo button. I have added the code to the Extended Valid Elements box and the editor.css to the template. xtypo works when I add the {xtypo ...} tags to both articles and category descriptions but the button only works in articles and not in the category descriptions.
Can you advise?

Hello

Mmm a little bit strange there...
I have tested it also on my local and it works fine on category description. So I'm not sure why xtypo button not working at your end.

Hi Brandt, I was checking this on my localhost too and I was also able to get this work with category description as erwin did. Please see the video in here d.pr/v/dM9G