Does the wheel work normally in other games?
Are you new to the game or did RBR work with your previous wheel? If you've played RBR before with another wheel, you may have to delete the profile and create a new one, although maybe you should still try things like "Redetect the wheel" (in the controller setup) or connecting the wheel to another USB port first to see if they make a difference (it goes without saying that you must not switch USB ports with the game running).
Have you installed/updated the latest firmware/drivers from the Thrustmaster website
https://support.thrustmaster.com/en/cat-wheels-en/ ?