Enlarged or magnified screen image

My screen image is magnified or enlarge so that it appears to show only about a quarter of the intended screen.  It was displaying properly until something I did or otherwise happened that I don't recall.  I experience this when using DirectTV Stream with Apple TV 4K (2nd Generation) HD and a Samsung 4K TV.  I've tried changing the picture quality in DirectTV Stream settings and Apple TV, trying various combinations with no success.  It only happens within the DirectTV Stream application, but none of the other stream feed applications, so I suspect it is a DirectTV Stream app issue.  Any thoughts?