I was setting up a single player session with 2 races, and I figured out that you can't set different time lenght for each one (e.g. the first race 15 min and the second 40 min), as the value setted in one overwrites the value of the other.
Added to this, I can't even start a second race, the "Drive" button is grayed out! I did Qualy and finished Race 1 by the way.
You're still in the same race session, so you can't Drive again. Go to session controls (antivirus looking guy next to the back button, top left) and go to the next session.
Yes, I know, but that button doesn't get you into the next session, in fact it doesn't do anything, while it's still clickable (notice the "Race 2" label on the top of 2nd screenshot, but I was in the first session). I think the whole multi-race session system is completely broken
