I am playing a full F2 season with 100% race lenght and race results are usually screwed up by IA drivers making a pit stop in race2, which does not require any pit stop at all. The cause of this problem can be the fact that IA drivers are using 2-3 set of hard tires during free practice, so this means that they use in free practice the sets of Hard tires which are supposed to be used in race 1 and race 2: as a result of this, IA drivers don't have any new set of Hard tires to use in race 2, so they are forced to make a pit stop. I think that if you prevent IA drivers from using more than 1 set of tires in the free practice session the problem would be solved, because they would have fresh tires for race 2 and they wouldn't need any pit stop.