Is this the to-be-expected behaviour, or is it a bug in kwin? I have a laptop, which I sometimes connect to an external monitor (via HDMI). When I switch between single and dual monitor display, using the keyboard shortcut (Fn+F4), I end up with the Plasma default wallpaper and all plasmoids disappear. The add plasmoids side-window still shows the plasmoids as being active, but I'm presented with a 'clean' standard screen on both displays.