I'm finding that on many races cars are behaving really weird, or getting DQ'd if I set a race to say 10 laps and then put a mandatory stop in. Examples to try: Imola - 10 Laps, Ultima Race, mandatory stop. Bathurst - 5 Laps (cos length), Porsche Cup car, mandatory stop. In both examples the AI do some strange things around pitting in - generally queuing up just past the pit on the last lap. Great for wins, but not so good for great racing. Known issue? It's easy enough to replicate...