Window.window cannot work as a target of Connections QML in GridView/RowLayout

Window.window attached property does not work as a target of Connections QML Type, when it is used in GridView.

Steps to reproduce the issue:

1. Run the attached reproducer, and drag the window around. The Global position value of each Rectangle will be updated accodingly.

2. Modify the target setting in Connections as below:

            // target: control.Window.window
            target: Window.window   // this will not work

3. Run the reproducer again, and drag the window around. This time the Global position will not be updated. The Connections seems not receiving the XChanged/YChanged signals from the top window.

The reproducer is implemented with GridView, but the issue can be reproduced with RowLayout as well.