Lerp with Coroutine doesn't behave as expected

A few Important notes:

• Lerp is not used in an Update() function. For specific reasons I am using a Coroutine.

• The goal is to move a transform from Point A (its current position) to point B. (which its location is random, for now, lets say its higher than point A.)

• After transform has arrived, an injected function is called.

• This Lerp is the last one out of a series of Lerps triggering one after the other.

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  The Bug:

• The Transform always arrives to Point B as expected. The function injected is not called 99% of the time, for an unknown reason. The weird thing is that sometimes it does actually call the function.

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  Things I Checked:

• Function is never null, it's always assigned correctly.

• I Tried multiple values for each of the params to see if there is a common behavior, there isn't. In some tries the function is called, in most of the tries it doesn't.

• I tried braking the While() loop if the transform reaches point B before the given duration, same results.

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  The Code:

   using System.Collections;
   using System.Collections.Generic;
   using UnityEngine;
   
   public static class LerpUtil
   {
         public static IEnumerator LerpPosition(Transform obj, Vector3 startPosition, Vector3 endPosition, float duration, OnAnimationFinish onAnimationFinish = null)
           {
               float time = 0;
       
               while (time < duration)
               {
                   obj.position = Vector3.Lerp(startPosition, endPosition, Mathf.SmoothStep(0, 1, time / duration));
                   time += Time.deltaTime;
                   yield return null;
               }
               obj.position = endPosition;
       
               if (onAnimationFinish != null)
               {
                   onAnimationFinish();
               }
       
           }
   }