Hello,
I have set up an orthographic camera in 3ds max.

With your demo app, i can see the camera is orthographic (it's ok)

In my project using openfbx, the camera has an enum value of 0 (perspective)
auto enum_value = ofbxcam->getProjectionType();
May be the error is because the property is called "CameraProjectionType" in your demo, and in your code you seems to get "ProjectionType" property.
I think the default value (perspective) is always used because of this naming mismatch.
