Problem with disabled collision in 2D objects

Hi everybody,in my game there's a power-up that when actived it makes you invincible deactivang obstacles' colliders.The problem is when i collide with the obstacles while my power-up is on my player,the player doesn't die but he gets stuck, such as the obstacle's collider stops the player,but it is deactivated! And if this may help the player has attached a rigidbody2D with the fixed angle actived.

This code is attached to the player and it creates the power-up

 int inst=0;
     public Vector3 cercPos; //position of the shield 
     public GameObject scudoCerc; //the shield that protects the player
     public bool createdScudo;//if the power-up is on
     public float diffTime;
     public CircleCollider2D colzLama; //obstacle
     public BoxCollider2D colzFreccia;//obstacle
 void Update () {
         cercPos=new Vector3(transform.position.x,transform.position.y,0);
     if(inst<2)
         {
             Instantiate(scudoCerc,cercPos,Quaternion.identity);
             inst+=1;
         }
         if(createdScudo==true)
         {
             diffTime-=Time.deltaTime;
             colzLama.enabled=false;
             colzFreccia.enabled=false;
         }
         if(diffTime<=0)
         {
             createdScudo=false;
             colzLama.enabled=true;
             colzFreccia.enabled=true;
         }
     }
     void OnCollisionEnter2D(Collision2D colz)
     {
         if(colz.gameObject.tag=="shield" && createdScudo==false)
         {
         inst+=1;
             createdScudo=true;
               StartCoroutine(ActiveScudo());

         }
         if(colz.gameObject.tag=="lama" && createdScudo==true)
         {
             //rigidbody2D.AddForce(new Vector3(1,0,0)*0.1f,ForceMode2D.Impulse);
         }
         if(colz.gameObject.tag=="freccia" && createdScudo==true)
         {
             //rigidbody2D.AddForce(new Vector3(1,0,0)*0.1f,ForceMode2D.Impulse);
         }
     }
     IEnumerator ActiveScudo() //This is the timer of the power-up
     {
         createdScudo=true;
         yield return new WaitForSeconds(diffTime);
         createdScudo=false;
     }

What is wrong? I am stuck in this code by days. Thanks in advance :D