Same issue for me – works perfectly on Chrome and IE, but all uploaded fonts render in system default when opening in Firefox. I’ve disabled all pop-up/ad blockers, etc., and tried the disable/reenable method. Can you please share your response to the OP or advise if there’s something I need to do on my end? Thanks!
BTW – I have another domain (www.pcmsvcs.com) using WordPress with the UseAnyFont plug-in, and it works correctly in Firefox.
One thing: I am using CSS Hero ( http://www.csshero.org/ ) to customize the site’s css and have not assigned classes in the Use Any Font interface. The fonts show up fine in Safari but Firefox is defaulting to Open Sans
I’m working locally on my desktop. I just noticed that Firefox is not using the correct weight for one of my fonts WHEN I have to use text within the text area that came formatted with my WordPress theme. The same page appears fine in Chrome.
Interestingly, however, when my font (in both light and regular wts.) is placed within a Dynamic Widget, (this is on other pages) they do work in FireFox.