Always on top not working on fullscreen applications

Hello,

I have noticed that "always on top" does not work on fullscreen applications in xfce with xfwm4. If I have e.g. a virtual machine in fullscreen and want a terminal window from my host machine "always on top". It doesn't work. If I click on something in the virtual machine, the terminal window disappears.

However, it does work on Gnome with Mutter. Is there any possibilty to configure xfwm4 in a way, that "always on top" does work on fullscreen applications aswell?

Regards Diadochokinetic