When playing F2 Career and changing the car's setup in any way BEFORE qualifying (manually in the car setup menu, by loading a setting, or on the track, for example, by adjusting the brake balance), ...
Ideas
In F1 2020, there was no such problem in F2 qualifying. There was the same amount of fuel regardless of whether we changed the settings during training or not. The AI also had the same amount of fuel. Do it just like in that game!