Having an issue with procedural generation of obstacles

I was trying to spawn platforms every second, and it works once, but not after that. I have two empty gameObjects that are the instantiation points. Here is my script.

using System.Collections;

using System.Collections.Generic;
using UnityEngine;

public class SpawnRandomPlatforms : MonoBehaviour

// Start is called before the first frame update
public GameObject instantiated;
public Transform playerPos;
public Transform rightInstantiation;
public Transform leftInstantiation;
public float platformDistance;
public int platforms;
public bool isInstantiating = true;
public int onethousand = 1000;

void Start()
    while (isInstantiating == true)

        platforms = Random.Range(0, 1);

        GameObject InstantiatedPlatform = Instantiate(instantiated[platforms]);
        isInstantiating = false;
        Debug.Log("Has been insantiated " + platforms.ToString());

        if (platforms == 0)
            InstantiatedPlatform.transform.position = leftInstantiation.position;


        if (platforms == 1)
            InstantiatedPlatform.transform.position = rightInstantiation.position;

IEnumerator DelayInstantiate()
    yield return new WaitForSeconds(1f);
    isInstantiating = true;



Changed it to update and now it does it twice, but stops there