Qml font.styleName not working on windows

 
I have font(ttf) file , which I load in Qml using FontLoader. This font is successfully loaded. But when I use font.styleName. It is not changing font style

Text 
{
  text: "Client Name" 
  height: 23 
  font.pointSize: 20
  font.family: myLoadedFont.name 
  font.styleName: "Medium Oblique" 
}

On Mac, I am able to use font.styleName, but on windows it is not working. Is this windows platform specific issue in qt fonts.