qdockwidget docking is very slow for floating widgets

Docking speed is very slow for qdockwidgets that are floating.
Notice that this only happens on Mac.

How to reproduce:
1. Open the Main Window example in Qt creator.
2. add, setAnimated(false); in MainWindow's constructor. This is added to just make the problem more obvious.
3. Build and run the project.
4. Drag "green dock widget" around the window without releasing the mouse and notice that the docking speed is instant. Meaning that when you drag the green dock widget over a dock area, the widgets that occupy that area move instantly to make space for the green dock widget.
5. Click float button for green dock widget to make it a floating window, and now drag the window over different dock areas and observe how the widgets that occupy docking areas do not instantly move to make space, but there is a 1-2 second delay.