With "environmental reflections" on, inc low, during multiplayer sessions over saturates the brightness to 100% white screen within the game world. The ui is fine except for the camera window which also displays the issue. My system: AMD Ryzen 5 5600x Nvidia RTX 3070 ti with latest drivers installed 16gb memory Windows 10, up to date
Is it possible that you're using old content, not converted to DX11? Could be a shaders problem too. Try deleting the content of the folder Shaders and Cbash located in ..\rFactor 2\Userdata\Log\ Don't worry, those are temporal files that rF2 will create again.
Deleting the shaders and cbash files didn't work. However; I found the problem, I had to turn off "environmental reflections" to get it working.
Then, the reason should be that the circuit version must be DX9 compatible, because the DX11 version isn't public.