Trigger won't read my Bool change

Hello there

First off I am making a block game where blocks stack till they hit a trigger I made at the top of the level. The blocks spawn above the trigger so I used a bool that changes after a set time. The trigger should recognize the true statement and do nothing, however if it detects false it ends the game.

So I am confused as to how I can make a trigger check a bool of a object that got instantiated.

Here is what I want my code to do:

When the object gets instantiated, it sees that my bool "isFalling" is true,

after a few seconds(falling time) it will automatically change to false.

If the trigger detects false at all it will call my game over code.

Here is my code for both scripts: Trigger Code: public class Boundary : MonoBehaviour {

     private GameController gameController;
     private ShootableBlock block;
 
     void Start()
     {
         GameObject gameControllerObject = GameObject.FindWithTag("GameController");
 
         if(gameControllerObject != null)
         {
             gameController = gameControllerObject.GetComponent<GameController>();
         }
     }
 
     void OnTriggerEnter(Collider entity)
     {
         if(entity.CompareTag("Block") == false)
         {
             gameController.GameOver();
         }
     }
 }

Then my Block code(object being instantiated): public class ShootableBlock : MonoBehaviour {

 public int currentHealth;

 public int scoreValue;
 public float fallingTime;

 
 private GameController gameController;
 public bool isFalling;

 void Start()
 {
     StartCoroutine( IsNotFalling());

     GameObject gameControllerObject = GameObject.FindWithTag("GameController");

     if(gameControllerObject != null)
     {
         gameController = gameControllerObject.GetComponent<GameController>();
     }

     if(gameController == null)
     {
         Debug.Log("Can't find 'Game Controller' script");
     }
 }

 public void Damage(int damageAmount)
 {
     currentHealth -= damageAmount;

     if(currentHealth <= 0)
     {
         Destroy(gameObject);
         gameController.AddScore(scoreValue);
     }
 }

 IEnumerator IsNotFalling()
 {
     isFalling = true;

     yield return new WaitForSeconds(fallingTime);

     isFalling = false;
 }

}

Help is much needed thanks to anyone that helps.

Also not sure if I should use OnTriggerStay instead what do you guys think?