Mobile Firefox has a problem with the system font "Georgia"?

I’m currently building a prototype in Axure RP 10 and I’m quite confused, that the prototype looks as it should in Safari (Mobile), but loads a complete different font in Firefox (Mobile). I use “Georgia”, a common system font and Firefox Mobile shows a sans-serif. (Firefox Desktop works fine.)
Even Chrome Mobile shows a few differences…

Is there a good solution for this?
Is it possible to define alternate fonts in Axure, like in CSS?

Thank you!