AppBar reserves too much space

[MojoDK]

Fisrt of all - thank you for creating this. I've struggeled with creating an AppBar myself and it is a pain in the butt :)

I have 4 screens. If I please the appbar on screen 1,2 and 3 everything is perfect.

If I place it on screen 0, there's tons of space between the appbar and my fullscreen Outlook....

https://app.screencast.com/Oi6lmuJ31Kb83

Any idea why?

Thanks. :)