Firefox relies on gtk for for those integrated buttons. It’s maybe worth checking that your gtk theme is set to breeze in System Settings > Colours and themes > Application style > GNOME/GTK Application Style (top right …), and that firefox is set to use the system theme.
Firefox relies on gtk for for those integrated buttons. It’s maybe worth checking that your gtk theme is set to breeze in System Settings > Colours and themes > Application style > GNOME/GTK Application Style (top right …), and that firefox is set to use the system theme.