QQuickView has severe problems when being clipped inside a NSView

when I embed a QQUickView into a NSView (by using QPlatformNativeInterface, "setEmbeddedInForeignView" etc.), my QQuickView shows very problematic behaviour: for one, it flickers like hell whenever it is clipped by its superview and secondly, its contents are shown at wrong positions if QQuickView has either a negative x-position or it's bottom extends over the superview's bottom.

I could deal with the wrong content placement in my project, but the flickering is a total showstopper for me. Please help me!

I attached a small QtCreator project, which shows the problematic behaviour.