Noting that the exact same behavior doesn't happen with Unity 2D, but it's still 'wrong' in that there is a window present which can't be seen. This could be what is causing this problem in Unity 3D.
Noting that the exact same behavior doesn't happen with Unity 2D, but it's still 'wrong' in that there is a window present which can't be seen. This could be what is causing this problem in Unity 3D.