When setting the default orientation to "Portrait", but running it in desktop mode on the Surface 4, starting in landscape orientation. In this case the orientation will be reported to be Portrait, even though the OS has forced it to be in landscape.

Repro steps:
- Set the default orientation to Portrait in Player Settings.
- Put your Surface tablet in desktop mode (not tablet mode) and out it in landscape left orientation.
- start the app, it will open in a window, forced into landscape by OS regardless of default orientation.
- the app will wrongly report "Portrait" as its orientation.
- rotate the device to another orientation, the orientation will be updated correctly.

So it seems as if Unity knows the correct orientation at all times, but is not updating the default orientation API correctly on startup in these cases.