Below are a couple of videos showing the graphics issues I have when running long races:
Daytona: I was trying to simulate the 24hr endurance race. Gave up due to the track disappearing.
https://youtu.be/0zIx6v34KPw
Indy Oval: Long races always result in a CTD.
https://youtu.be/6K7-ka4c9qU
Sadly, this is still happening.
I used to get this on quite a few tracks and at one stage I had to follow the blue sky path because the road disappeared as well. Also noticed if you are doing a race and the walls, grandstand whatever starts to disappear then it is a guarantee that once it starts it will happen same place on every lap. I would get it on Daytona but could do a long race on Nurburgring without issue.
I see that one time when i use too high graphic configuration over the spec of my PC, i use recommended graphic configuration and never see that again.