Framerate drops!!

Hello to all, today i will talk you about a problem that’s hitting me since the release of the game: FPS drops! First of all I want to share with you my PC specs to ensure that this is not an hardware problem.

-Video card: Asus Expedition GTX 1050 TI
-Processor: Intel core i5 4690 3.5 Ghz
-RAM: Kingston 12GB (x1 4GB//x1 8GB)
-Motherboard: MSI H81M-P33
-Power supply: Corsair VS 650w
-Hard Disk: Kingston 1TB

I play with a 60hz monitor in 1080p 60fps with Vsync, all graphics put on high,very high and some things on ultra.

When i get into the game, it’s all running smoothly 60fps with zero problems. Even on the most heavy races with 24 rivals and heavy rain,going 300kph i always have 60 fps. The problem occurs when i navigate inside the game menu, expecially while selecting a car from the garage and after returning from an auction, for no reason,the FPS rate drops down to 30 and even 20 and it’s reeeeally annoying!!! And after that drop when i try to race, everything runs from 30 to 50 fps,and not smooth 60 anymore. I don’t know what’s the real problem of it. I tryed to reinstall video drivers, to update CPU drivers,to run an antivirus,to reinstall the game,to uninstall msi afterburner and asus gpu tweak 2, i tryied to low down the graphics and to disable the vsync but nothing to do… always if I navigate too much inside my garage the fps drops instantly and i have to restart the game to solve that problem,that occurs again while doing same things. Can anyone help me? I can’t stand that anymore! I paid all that money for the worst optimized game ever!!! i have never seen a game with so many problems!