OnColliderExit2D doesnt seem to execute

Soo, I am making a 2D game and currently was making platforms, managed to make them and I made a script, which when the character gets on top of the platform, he becomes child of it so he moves with it. Now when I wanted to create the exiting platform bit, I found out it just doesn't trigger, for whatever reason. Here is the code, hope it's some silly fast to solve mistake! :D

 using UnityEngine;
 using System.Collections;
 
 public class MovingPlatformB : MonoBehaviour {
 
     // Use this for initialization
     void Start () {
     
     }
 
     void OnCollisionEnter2D  (Collision2D  other) {
         if(other.gameObject.tag == "Player") {
             other.transform.parent = transform;
             Debug.Log ("fock");
         }
     }
 
 
     void OnCollisionExit2D (Collision2D  other) {
                 if (other.gameObject.tag == "Player") {
                         other.transform.parent = null;
             Debug.Log ("???");
                 }
         }
 
     // Update is called once per frame
     void FixedUpdate () {
         transform.position = MovingPlatform.platformPosition;
     }
 }