Not sure whether it can fix the font problem, but in general Flatseal allows you to customise permissions for installed flatpaks.
https://flathub.org/apps/com.github.tchx84.Flatseal
If you are in Europe, try dns0: https://www.dns0.eu/
Not sure whether it can fix the font problem, but in general Flatseal allows you to customise permissions for installed flatpaks.
https://flathub.org/apps/com.github.tchx84.Flatseal