A few days ago I was using SD on a commercial flight (I was a passenger).
While on the ground I selected "Fly" and saw the expected highly detail map of the airport and the aircraft's movement along the taxiway.
After a few seconds the display changed to a totally blurred depiction of something. I recycled SD but the same happened.
On the third occasion of this happening I tried to zoom out to see what was being displayed.
It looks like SD has switched to the CAA chart style but the zoom setting was still set to "high" as would be required, presumably, for the detailed airport layout. So hence the very "blurred" graphics.
Once airborne normal SD displays resumed and the issue didn't reoccur on landing. The destination airport high detail map displayed normally.
SD version 126.96.36.19940
Android Galaxy S3