Hi Christopher, It has occurred to me that you might not have seen my follow up messages if you are not subscribed to the bug. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1025350
Please comment on the bug report if you have any more useful information on the problem. I had said on Dec 3rd .... "Just tested font changing for qt6ct itself and qtcreator, and fonts are changing just fine, so I can't reproduce this problem. However, I'm using Xfce, so maybe this is a Gnome issue? Fonts do take a little while to change though. Is qt5ct working for you?" and.... "One further thought. I assume you are using TrueType fonts. Which specific font(s) are you having the issue with? I'm using liberation fonts here. {fonts-liberation2}" Regards, Peter B