Your NVR can only handle so much bandwidth (data), you need to adjust your resolution, FPS and bit rate so you get the best picture quality possible and still get 2x2 in multiscreen. Set the resolution lower (720p), lower FPS (15 is good) then increase the bit rate till you no longer get 2x2, then slightly decrease the bit rate till 2x2 comes back, this would give you the best picture quality plus 2x2 multiscreen.