when adding a TrackOverlay for doing some measuring, ms will place the features.
But when setting the TrackOverlay to nothing or a new instance of a TrackOverlay the Features are still displayed. And when moving the MapView these Features freeze and will be displayed at screen position. They do not move/scale like normal features on FeatureLayer.
The code is from V10 ported to V12 only DrawCore is chenged to DrawTileCore.