Firefox seemingly very recently shipped their own titlebar controls buttons, which worsens even further the lackluster OS integration. In the screenshot you see my regular control buttons on the window to the left (default KDE Plasma theme) and the new custom buttons Firefox is serving now.
Would anyone know how to undo that change in about:config or anywhere else?
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.
My GTK Theme is already set to “Breeze”.
And my Firefox Theme is set to “System”.
Thanks though.