With regard to fonts, the Open Source community can perhaps suggest more practical application. There are not, to my understanding, specific OS fonts. Open Source applications are typically ported to Windows, Mac and Linux, where the Mac OS is a version of Linux not named Linux. Is there a font that is common to all? I cannot believe you need one, as portable as fonts are these days.
Why Donald is having problems isn’t obvious to me because I had a different outcome. Donald’s issue is likely addressable, it will take some time and some poking around to find the solution.
Richard