I simply do not know. I would have to see the 'shift' you refer to be able to comment further.
A wild guess here, depending on how large the map is, is that a device in the lower right has some precedence or value better than others and becomes a 'focal point' for the map so the map center focuses on that device.
This could also be the Map Properties -> Control ... where you select options like "Enable Pan and Zoom" or "Disable" impacting how it is drawn.
