Forzathon: Misfit Mayhem / Requred division not available

Just wanted to clear the Misfit Mayhem event and the first requirement is to win a race in a Forza Specials division car. Problem is: That division does not exist, at least in my version. The problem is not that I don’t own one, the division literally doesn’t exist, even when I try to buy a matching car.

Anyone else has the issue or a solution to it? Maybe it’s just a naming error and it should be another division?