How to prevent continuity camera from correcting orientation?

I am using an AVCaptureSession in a macOS application for real time scan/image feature detection. Since most iPhone cameras are better than most Mac cameras I also support Continuity Camera. This generally works very well.

However, when the user wants to point the iPhone/Continuity camera down at a document on the desk, as is most likely the case, the Continuity camera flips and 'corrects' the video orientation to landscape.

How can I prevent that? I am using more or less the exact architecture that apple provides in the Supporting Continuity Camera sample app.