Original User: bern2rd
I removed this line and it fixed the problem.
//myMap.ZoomDuration = TimeSpan.Zero;
This line was added because it solved the problem where when we set the extent constraint the zoom-in feature started to behave strangely. When clicked on the Zoom-Extent it goes to the full extent without a problem but as soon as you start zooming in it will not response. This problem goes away after you attempt to zoom-in about 5-6 times. When I removed this extent constraint everything worked flawlessly but of course without the constraint that we need.
FullExtent.ConstrainedExtent = fullExtentEnvelope;
btw, it has nothing to do with the rotation.
Thanks,
Bernard