Can't hit collider when rotating while go along with wall

Question

as you can see in the picture, my character go along with wall. it detected wall by capsulecast. (the direction of capsulecasting is forward of character)

when it go straight, capsulecast hit the wall and it's correct. when it go parallel with wall, capsulecast hit nothing and it's correct. but if my character turning at that moment, it hit nothing..

how can i solve this?

(sorry for my english ;-|) and here is my code for detect obstacle.

horRayLength = Mathf.Abs(horMoveAmount.magnitude) + skinWidth;
isHit = Physics.CapsuleCast(capsuleTop, capsuleBottom, capsuleCollider.radius, horMoveAmount.normalized, out raycastHit, horRayLength, horCollisionMask);
if (isHit)
{
    if (raycastHit.distance != 0)
    {              
            var projected = Vector3.ProjectOnPlane(horMoveAmount, raycastHit.normal);
            moveAmount.x = projected.x;
            moveAmount.z = projected.z;
    }
}

transform.Translate(moveAmount, Space.World);