Endless Runner Overlapping Platforms Bug

Hello! I'm a new Unity user and would greatly appreciate any help you can provide answering my question or leading me to the answer. I'm making a 2D endless runner, and my platforms bunch and overlap like this:

Here is my code. It's sorta long, but I think the problem may be towards the end after the heightChange variable calls.

 using UnityEngine;
 using System.Collections;
 
 public class PlatformGenerator : MonoBehaviour
 {
     public GameObject platform;
     public GameObject[] platforms;
     public Transform generationPoint;
     public float distanceBetweenMin;
     public float distanceBetweenMax;
     public ObjectPooler[] objectPools;
     public Transform maxHeightPoint;
     public float maxHeightChange;
 
     private float distanceBetween;
     private float platformLength;
     private float minHeight;
     private float maxHeight;
     private float heightChange;
     private int platformSelector;
     private float[] platformLengths;
 
 
 
     // Use this for initialization
     void Start ()
     {
         platformLength = platform.GetComponent<BoxCollider2D>().size.x;
         platformLengths = new float[objectPools.Length];
 
         for(int i = 0; i < objectPools.Length; i++)
         {
             platformLengths[i] = objectPools[i].pooledObject.GetComponent<BoxCollider2D>().size.x;
         }
 
         minHeight = transform.position.y;
         maxHeight = maxHeightPoint.position.y;
     
     }
     
     // Update is called once per frame
     void Update ()
     {
         if(transform.position.x < generationPoint.position.x)
         {
             distanceBetween = Random.Range(distanceBetweenMin, distanceBetweenMax);
             platformSelector = Random.Range(0, objectPools.Length);
 
             heightChange = transform.position.y + Random.Range(maxHeightChange, -maxHeightChange);
 
             if(heightChange > maxHeight)
             {
                 heightChange = maxHeight;
             }else if(heightChange < minHeight)
             {
                 heightChange = minHeight;
             }
 
 
             transform.position = new Vector3(transform.position.x + (platformLengths[platformSelector] / 2) + distanceBetween, heightChange, transform.position.z);
 
             GameObject newPlatform = objectPools[platformSelector].GetPooledObject();
 
             newPlatform.transform.position = transform.position;
             newPlatform.transform.rotation = transform.rotation;
             newPlatform.SetActive(true);
 
             transform.position = new Vector3(transform.position.x + (platformLengths[platformSelector] / 2), transform.position.y, transform.position.z);
         }
     }
 }

Thanks for taking the time to look over my question.