Why is the object not activated after the ***.gameObject.SetActive(true); function?

Question

C++ / C#

The script was supposed to deactivate child objects at startup (which it successfully does), and after the collide with objects of the Ground, Side, LeftSide tag, activate it back (which it does not successfully do).

using UnityEngine;
using System.Collections;

public class EnablingColliders : MonoBehaviour
{
    private Transform childObj;
    private Transform childObjSecond;
  // Use this for initialization
  void Start ()
  {
      childObj = transform.FindChild("Collider");
      childObjSecond = transform.FindChild("Effectors");
        childObj.gameObject.SetActive(false);
        childObjSecond.gameObject.SetActive(false);
        
  }
  
  // Update is called once per frame
  void Update () {
  
  }

    void OnCollisionEnter2D(Collider2D collision)
    {
        if (collision.transform.tag == "Side" || collision.transform.tag == "LeftSide" || collision.transform.tag =="Ground")
        {
            childObj.gameObject.SetActive(true);
            childObjSecond.gameObject.SetActive(true);

        }
    }
}

Answer 1

childObj.FindObject() is essentially hidden behind the call to childObj.gameObject , and the search will not find disabled objects.
Save the reference directly to the GameObject , not to the Transform