Hi Leo
Might be a silly question but you do have sponsors set correct? They never expired and you forgot to renew them? That will cause you getting $0 at the end of the race.
No that can't be it because I actually got my bonus money after the race, I have 5 races until my sponsors need re-signing. Also during the race one of my competitors retired on the penultimate lap even though he had a fresh car and engine. It was a strange race tbh...