See the attached video — sometimes when dragging an event, the grey shadow of the event you are dragging does not appear, and when that happens, upon releasing the mouse, the even goes to an incorrect time (and not the time that you were trying to drag to). Usually it ends up at 12am.
We thought it was an issue with our implementation, but we were able to recreate this bug on the Daypilot demo as well.
Any ideas of how to prevent this behavior are welcomed!