My crashing and lockups are from loading

I have been playing around to see when my issues happen.
It seems that whenever loading the game or races takes a longer time, sometimes a lot longer. I will have major issues with serious freezing, lockups extremely erratic FPS and even crashes.
When I first got the game it played flawlessly but after having it for a while and as I progressed, things have gotten really bad.
Sometimes everything loads really fast and it plays smooth as butter at 175 FPS @3840 2160 4K.

But if it stutters, freezes and takes a long time to load the game is absolutely unplayable.

Is it a save issue? After having the game longer and the saves change, can loading them become an issue? Is it sometimes not loading something properly?

I have never seen a game so erratic as this.
One time you load it and play it is perfect. Usually it will stay that way for the duration. Even hours. Until I restart the game.
But another time I load it and it will just not work until a restart or two of the game.

I never know what I will get from one launch to the next.