Qt Quick Controls move WindowStayOnBottomHint to the front when using two displays

The attached .qml code when run creates two windows and one of them (full-screen size) is marked to always stay on the bottom while the other is just shown with no extra flags.

When I click on Button or Switch (and probably any control inheriting Control) which are placed in the background window, this background window is moved to the front and the other window is overlayed then.

It works as it should when only one monitor is connected to my PC, but when using two monitors it works as described above.
It also works as expected when I use MouseArea instead of Button.

This recording https://docs.zohopublic.eu/file/62c501893030a96664a4fa93fe66aae349244 
shows also some weird stuff going on with the Switch item.

Maybe the issue applies to all platforms, but I tested only on windows