Instantiated Game Objects' Script Won't Update

I am currently developing my first game (falling platformer) and I’ve got an object pool of platforms that randomly spawn as the character falls. I have set the game up so the camera remains static while the platforms move up. In an attempt to create the illusion of falling, I have set up an invisible collider about halfway down the screen so that when the player lands on it, the velocity of the platforms should increase. However, the velocity variable in my platform behaviour script attached to my platform prefabs will not update.

Here is my platform behaviour script which is attached to my platform prefabs as well as my platform generator game object:

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

public class PlatformBehaviour : MonoBehaviour
{
    public float riseSpeed;

    Rigidbody2D rb;

    public GameObject fallCollider;
    FallCollider colliderScript;

    // Start is called before the first frame update
    void Start()
    {
        riseSpeed = 2;
        rb = GetComponent<Rigidbody2D>();

        colliderScript = fallCollider.GetComponent<FallCollider>();
    }

    // Update is called once per frame
    void Update()
    {
        Rise();

        if (colliderScript.playerTouching == true)
        {
            riseSpeed = 4;
            
        } else
        {
            riseSpeed = 2;
        }            
    }

    private void Rise()
    {
        rb.velocity = new Vector2(0, riseSpeed);
    }
}

And here is my collider script which is attached to the invisible collider:

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

public class FallCollider : MonoBehaviour
{
    public bool playerTouching;

    private void OnCollisionEnter2D(Collision2D collision)
    {
        if (collision.gameObject.tag == "Player")
        {
            playerTouching = true;
        }
       
    }

    private void OnCollisionExit2D(Collision2D collision)
    {
        if (collision.gameObject.tag == "Player")
        {
            playerTouching = false;
        }
    }

}

When I run the game and pause it when the player is on the collider, I can see the riseSpeed variable updates for the PlatformGenerator object but does not update for each of the instantiated platforms. Any guidance would be extremely appreciated as I have been racking my head over this for the last few days.

Since you never initialized fallCollider field in PlatformBehaviour:

Your generated platforms don’t have reference to fallCollider.

On the other hand, your generetor object have reference to fallCollider because I guess you set it manually using editor.