instantiated object doesnt recognize ignore collision

Hey all,

I've been trying to ignore collisions with specific elements in game.
And I succeeded it but when a objects instantiates, it first doesnt ignore collision which it should.
After first hit with other objects, it starts to ignore collisions.
But it should always ignore it.

Code (CSharp):

1. void OnCollisionEnter2D(Collision2D other)
2.     {
3.        
4.         if(other.gameObject.tag == "redBall")
5.         {
6.             Physics2D.IgnoreCollision(other.gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
7.             Physics2D.IgnoreCollision(gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
8.         }
9.         else if(other.gameObject.tag == "greenBall")
10.         {
11.             Physics2D.IgnoreCollision(other.gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
12.             Physics2D.IgnoreCollision(gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
13.         }
14.         else if(other.gameObject.tag == "blueBall")
15.         {
16.             Physics2D.IgnoreCollision(other.gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
17.             Physics2D.IgnoreCollision(gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
18.         }
19.          else if(other.gameObject.tag == "blackBall")
20.         {
21.             Physics2D.IgnoreCollision(other.gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
22.             Physics2D.IgnoreCollision(gameObject.GetComponent<Collider2D>(), GetComponent<Collider2D>());
23.         }
24.  
25.     }

This is my ignore collision code. It works fine with other moving objects, but not the one just instantiated.

I don't know why it happens.