onclick.addlistener only works once

I have a bunch of instantiated UI buttons in my canvas. I am trying to Find one of the buttons and attach onclick.Add listener to it. I am able to attach the listener with a coroutine, but it only works.

I am using a co routine instead of adding onclick.addlistener in start() functions because, my instantiated buttons are spawned later.

Below is the script I am using for it.

using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI;

public class Product_Instance : MonoBehaviour {

 public Button button;


 IEnumerator butt () {

     button = GameObject.FindGameObjectWithTag ("Cisterns").GetComponent<Button> ();
     GameObject open = GameObject.FindGameObjectWithTag ("Open_Vertical");

     button.onClick.AddListener(() => {
         open.GetComponent<EasyTween_Product_button> ().OpenCloseObjectAnimation ();
     });
     yield return new WaitForSeconds(0.5f);

 }
 
 // Update is called once per frame
 void Update () {
     button = GameObject.FindGameObjectWithTag ("Special Series").GetComponent<Button> ();
     if(button !=null){

         StartCoroutine ("butt");

     }
         
     
 }

}