Unity - Can't create multiple objects with a delay between creation

Question

I'm trying to make the coroutine spawn one object at a time every 0.2 seconds, but when I run the coroutine, it spawns multiple objects at once without any delay. How can I fix this and achieve the desired result?

My code:

        if (shotExtender > 0)
    {
        StartCoroutine("Timer");
    }
    else
    {
        StopCoroutine("Timer");
    }

Coroutine

    IEnumerator Timer()
{
    while (objCounter < 3)//it should spawn only 3 objects
    {
        yield return new WaitForSeconds(0.2f);

        GameObject bullet = PhotonNetwork.Instantiate(bulletPref.name, bulletPosition, Quaternion.identity);

        objCounter++;
        Debug.Log("objCounter: " + objCounter + " maxBullets: "+maxBullets);
    }
    objCounter = 0;
    shotExtender = 0;//This stops the coroutine
}

Answer 1

Try taking out the object counter resetter and the shot extender resetter outside the coroutine. I believe that the if statement is being accessed multiple times generating multiple coroutines before the first one has even finished!

   if (shotExtender > 0)
{
    StartCoroutine("Timer");
    objCounter = 0;
    shotExtender = 0;//This stops the coroutine
}

Answer 2

If this code runs inside the update

if (shotExtender > 0)
{
   StartCoroutine("Timer");
}
else
{
   StopCoroutine("Timer");
}

You must finish the condition before starting the process like this

if (shotExtender > 0)
{
  shotExtender = 0;
   StartCoroutine("Timer");
}
else
{
   StopCoroutine("Timer");
}