Its a known bug in the core of the physics engine at the moment, the car bouncing up however was intended, maybe they will get around to finding the cause one day and find a way to patch it for people, it doesn't happen enough to be super annoying thankfully, just the occasional WTF moment eh
Nothing wrong with it. The track marshall on the left is just using "the Force" to save the car from doing a rollover. So he don't have to recover a wrecked car.
Right up to the point of funkyness I think it acts quite well tbh, I think that is probably why given the other things which could do with a lick of paint this issue hasn't made it onto the priority list yet.