The active aero extends on this car after 100kph thank goodness but it is supposed to tuck in at around or just above 200kph to reduce drag. At high speed corners, it comes back up again.
During braking, it extends as it should so the issue is active aero modelling while accelerating at different speeds.
The second issue is with the factory gear ratios. IRL, it is already shooting past 200mph or 321kph in 7th gear whereas in the game, it is still trying to redline in 6th gear while trying to hit 200mph. So the gear ratios and power to weight ratio or acceleration in the top two gears is wrong.