Minimize button looks like maximize button in windows that use GTK3 client decorations. This happens only if maximize button is not used (using minimize+close only): gsettings set org.gnome.settings-daemon.plugins.xsettings overrides "{'Gtk/DecorationLayout': <':minimize,close'>}"
Pushing the button minimizes the window though although the icon looks like maximize button. If the window isn't using client side decorations it uses the correct icon for minimize button.
Minimize button looks like maximize button in windows that use GTK3 client decorations. This happens only if maximize button is not used (using minimize+close only): gsettings set org.gnome.settings-daemon.plugins.xsettings overrides "{'Gtk/DecorationLayout': <':minimize,close'>}"
Pushing the button minimizes the window though although the icon looks like maximize button. If the window isn't using client side decorations it uses the correct icon for minimize button.