Solved

No prize money

I finished 3rd and 4th in my leagues race just now and received £0 prize money. I did get sponsorship but lost a tonne of cash due to the missing prize money.

Can you provide more information?

Sponsors only give out prize money if you meet the race objectives. You always get your guaranteed income, aka the primary sponsor's token income and secondary sponsor's income amount. Their bonus amounts are considered prize money.

Ahh, I have always assumed "prize money" was from the "FIA" for your race finishing position. So is this actually the race bonus from sponsors? That would make sense then since my target is usually to finish the race but for some reason became to win this time.

Correct! The prize money is the race bonus from sponsors.