QtWayland.Compositor: multi-screen, shellSurfaces maximize to wrong output

In the multi-screen example no matter which output a shellSurface is on it will maximize to the first output
(but with the correct size of the output it was on)

Setting output property does not help (and seems to be for something else in that case).
Using setPrimary() does not help.

Is there an alternative approach to handling multi-screen rather than adding the surface to all outputs?