All the fonts can be change in the Typography section in X > Launch > Options > Typography. If you already added the fonts in the templates section, then the font manager must have been turn off. Please check out this link to know more about the font manager:
Please try to enable/disable the font manager and see what happens. If the changes is not applying anything, maybe you have installed caching plugins. Please clear the plugin cache and test again.
If nothing works, please provide us the url of the site so that we can take a closer look.