When the drag is started a rectangle is drawn at the cursor to indicate the drag. When the drag is over not on any drop target, the rectangle should return to the component at which the drag was started. However, on the mac the rectangle is returning to the wrong coordinates. Probably this is due to the fact that on mac the zero for an y-coord is at the bottom.
A little test is attached. To reproduce an issue you should start a drag form the textfield, drop it anywhere on the frame and see how the rectangle is moving to the wrong place.