Can't get director mode to work consistently during AI races?

I press 'insert' while watching CPU races, some times it will actually work and switch cars and whatnot during the race, other times it will only stay with 1 car even though I see the director symbol come up. Anyway to make this work more consistently?

There is a bug with the game where it tends to only work in the first race.

Ah, I see. Thanks for the reply