short version - two cars from wheelspins vanished
Xbox One X. Just started FH5, it loaded into the situation where the EventLab names were not showing. I bought the Forzathon shop items including the wheelspins. I did the wheelspins, the super wheelspin included a Pagani Huayra FE and a Porsche 914/6. I exited the game to home screen. I loaded the game again and the EventLab names were present. The two Forzathon shop cars were in my garage but I did not have the two cars from the wheelspins nor did I have the wheelspins available again and I am unable to buy the wheelspins from the shop because I’ve already bought them.
I don’t care, it doesn’t affect me at all really, but it’s not right.
This is why I generally (always before exiting the game) after finishing everything what I wanted to do, go into my garage, exit the garage, go back into it again, exit it again and finally go back in again (not kidding!) - this is just to force the game to save everything correctly. This behaviour of mine - after all these years - is so deep inside me that most times I do not even notice it anymore. Because NOT after every in-game action the game is saving your progress.
There is no official list - but I know for sure that is saves after every race you finished. Obviously it also saves after you buy something from Forzathon Shop - but not after a wheelspin.
This is a known issue for many Forza games - probably going back to FH2. Sad but true!
Playing on XSX.