Whatever is happening it's not starting in VR properly. I recall ACC was one of the finicky games that required either SteamVR already started or not started and if you got it wrong it did the wrong thing. So try the other way to what you were doing already and I guess you were trying with SteamVR already started so try it without VR started and then launch the game and see if it asks you about VR mode and starts that way.
The performance was far too low to be usable in VR without it being continuously at 45 fps anyway so its not something I drove for more than testing since it makes me motion sick due to the low FPS.