Pages 6-49 and 6-50 answer the question I think. At least they way what the system should do, but can't say you are doing what it says when you are trying to resume. 30+ years in IT myself, we had a term KBUE for keyboard user error as it was often relevant to this kind of glitch 
Can't cut and paste but maybe the system parameters when linked to your driving explain the behavior.
Can't cut and paste but maybe the system parameters when linked to your driving explain the behavior.