Collision normal from OnControllerColliderHit does not match surface

Hi all,

I am trying to get the normal of the ground under my CharacterController's feet. I use some code like the following:

 public class Character : MonoBehaviour 
 {
 private List<ControllerColliderHit> contactPoints = new List<ControllerColliderHit>();
 void Update () 
 {
     contactPoints.Clear();
     GetComponent<CharacterController>().Move(runVelocityPlusGravity);
     foreach(ControllerColliderHit hit in contactPoints)
     {
         Debug.DrawLine(hit.point, hit.point + hit.normal, Color.red);
     }
 }
 
 void OnControllerColliderHit(ControllerColliderHit hit) 
 {
     contactPoints.Add(hit);
 }
 }

On a flat floor (normal 0, 1, 0) I see the normal drawn constantly flicker between about (-0.7, 0.7, 0) and (0.7, 0.7, 0) - i.e it's up to about 45 degrees out.

I guess maybe this is the normal on the capsule of the point that's collided, but I'd like to get the normal of the floor. It seems like Unity must have this information at the time the collision takes place. Is this possible to find the actual surface normal without doing extra raycasts and such?

As a side I used this exact code on a previous version of Unity and if memory served it worked just fine.

Thanks!