Collision Problem with AVATAR

Hi there I have a problem with my avatar and my map ( imported from sketch up ).

Everytime I slide ( crouch ), my avatar can pass through wall. But when I run, my avatar can detect the collision.

What am I doing wrong ?

Here is my sliding code, maybe it is the problem?

THX

Please help me

public class SliderInputController : MonoBehaviour

{

 public float slidingDistance;
 public float slidingHeight;
 public float slidingSpeed;
 public AnimationCurve curve;
 
 private CharacterController characterController;
 private CharacterMotor motor;
 private float originalHeight;
 private Vector3 slideStartPosition;
 private Vector3 slideStatDirection;
 private Vector3 destination;
 private float currentTime = 0.0f;
 private bool isCrouched = false;
 private bool rightClick = false;
 
 private void Start () 
 {
     characterController = GetComponent<CharacterController>();
     motor = GetComponent<CharacterMotor>(); 
     originalHeight = characterController.height;
 }
 
 private void Update () 
 {
     if(characterController.isGrounded==true)
     {
     
     // Detection des touches
     if(Input.GetMouseButtonDown(1))
     {
         //Debug.Log("Crouch");
         characterController.height = slidingHeight;
         characterController.center = new Vector3(0.0f, -slidingHeight/2.0f, 0.0f);
         
         slideStartPosition = transform.position;
         
         destination = slideStartPosition + transform.forward * (slidingDistance + motor.movement.velocity.magnitude);
         destination.y = transform.position.y;
         
         rightClick = true;
         isCrouched = true;
         
         motor.canControl = false;
     }
     if(Input.GetMouseButtonUp(1))
     {
         //Debug.Log("want to get up");
         rightClick = false;
     }
     // Ici je traite les touches
     if(isCrouched)
     {
         if(currentTime < 10 )
         {
             currentTime += slidingSpeed * Time.deltaTime;
             transform.position = Vector3.Lerp(slideStartPosition, destination , curve.Evaluate(currentTime));
         }
         if(!rightClick)
         {
             // Space est relaché
             Debug.DrawRay(transform.position, Vector3.up * 2, Color.yellow);
             if(!Physics.Raycast(transform.position, Vector3.up, 2))
             {
                 ResetSlider();
             }
         }
     }
     }
 }
 private void ResetSlider()
 {
     Debug.Log("Is getting Up");
     characterController.height = originalHeight;
     characterController.center = new Vector3(0.0f, 0.0f, 0.0f);
     currentTime = 0.0f;
     isCrouched = false;
     motor.canControl = true;
 }
 

}