I posted this also on Steam forum but better to post here I guess :
I was out for a long time and just re-downloaded the Sim few days ago. It worked fine on monitor with Vulkan selected, but had no chance to make it work with my Oculus CV1 on VR, I had a black screen in Headset and the sim appear right on my monitor.
Switching to OpenGL fixed the problem, and also switching to the SteamVR version, but in both case I don't have the same quality and fluidity than with Vulkan and Oculus SDK in VR.
I'm using the last NVidia drivers (457.30) and don't really want to downgrade it for numerous reason (support of recent games).
If you can investigate this that will be great!