underMouse() not working with WA_TranslucentBackground attribute set on Windows

If Qt::WA_TranslucentBackground is set to a Widget, underMouse() function is returning false always on Windows, and is working fine on MAC. 

Steps to reproduce:

1. Execute the attached project. 
2. Point to any Icon on window. 
3. Slider will popup and disappear immediately because underMouse() is returned as false
4. On MAC, Slider will not disappear and undermouse() is returned as true.

Expected Result:

UnderMouse() should have returned as true same as output.