I had forgotten to add that I am running Wayland. Anyways, the problem is now fixed with latest updates (Possibly mutter (3.34.0-2) with changelog "Fixes starting up of gsd-xsettings on Wayland"?)
** Changed in: firefox (Ubuntu) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1843645 Title: Tiny UI fonts in Firefox (and Thunderbird) after update in Eoan. General interface font has no effect? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1843645/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs