Why does my character move when pressing Lshift but if I dont press it he plays the animation but stays in place?

 if (Input.GetKey(KeyCode.D) || Input.GetKey(KeyCode.RightArrow) && !isDead && !isHurting)
         {
             rb2d.velocity = new Vector2(runSpeed, rb2d.velocity.y);
 
             if (isGrounded)
             {
                 animator.SetBool("IsRunning", true);
             }
             Vector3 characterScale = transform.localScale;
             characterScale.x = 2;
             transform.localScale = characterScale;
 
         }
         else if (Input.GetKey(KeyCode.A) && !isDead && !isHurting)
         {
             rb2d.velocity = new Vector2(-runSpeed, rb2d.velocity.y);
 
             if (isGrounded)
             {
                 animator.SetBool("IsRunning", true);
             }
             Vector3 characterScale = transform.localScale;
             characterScale.x = -2;
             transform.localScale = characterScale;
 
         }
         else
         {
             if (isGrounded)
             {
                 animator.SetBool("IsRunning", false);
             }
 
 
             rb2d.velocity = new Vector2(0, rb2d.velocity.y);
         }
 
         if (Input.GetKey(KeyCode.LeftShift) && Input.GetKey(KeyCode.D) && !isDead && !isHurting)
         {
             rb2d.velocity = new Vector2(runSpeedSprint, rb2d.velocity.y);
 
             if (isGrounded)
             {
                 animator.SetBool("IsSprinting", true);
             }
             Vector3 characterScale = transform.localScale;
             characterScale.x = 2;
             transform.localScale = characterScale;
 
         }
         else if (Input.GetKey(KeyCode.LeftShift) && Input.GetKey(KeyCode.A) && !isDead && !isHurting)
         {
             rb2d.velocity = new Vector2(-runSpeedSprint, rb2d.velocity.y);
 
             if (isGrounded)
             {
                 animator.SetBool("IsSprinting", true);
             }
             Vector3 characterScale = transform.localScale;
             characterScale.x = -2;
             transform.localScale = characterScale;
 
         }
         else
         {
             if (isGrounded)
             {
                 animator.SetBool("IsSprinting", false);
             }
 
 
             rb2d.velocity = new Vector2(0, rb2d.velocity.y);
         }