Weird problem with referencing game manager

I'm trying to reference my game manager script, but it's not working. Weird thing is, all I did was make something depend on a variable in the game manager, and both that thing and something else, unrelated, broke.

In my game, you get score by shooting objects that spawn that each have different random speeds. In the Target script (attached to the spawned objects), the speed of each object is determined by a method that returns a number from a random range. Then when it's shot, it tells a method in the Game Manager to update the score. It uses GetComponent to reach the game manager.

This all worked fine. until the fire nation attacked

I want to add different difficulties, so I made a difficulty variable in the game manager. I want the range used to determine speed to be different depending on the difficulty. So i replaced the one line that returns the speed with if statements that have different ranges depending on the difficulty. And THAT is when everything broke.

The if statements couldn't reference the difficulty variable from the Game Manager, even though it was able to reference a method from the GM just fine when it tells it to run the update score method. Not only that, but when I used the if statements in the random-speed method, the code that referenced the GM update-score method stopped working, even though it's in a completely different method! Both are fine syntax-wise, but when the game is running it shows the message "Null reference exception: Object reference not set to instance of an object", which makes me think it can't reference the GM for some reason.

Also, I've tried making a static variable in the GM and reference that to get the difficulty variable and use the update-score method, but then nothing works even without the new if statements, idk why.

The code shown here is only parts that are relevant, i removed other methods that arent related to the problem so it doesnt take up the whole screen. Full code here https://pastebin.com/DUZ51CgK

Ty in advance

relevant Target code:

     using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     
     public class Target : MonoBehaviour
     {
         private Rigidbody2D targetRb;
         public GameObject player;
         public GameManager gameManager;
         public int pointValue;
         [SerializeField] private float minSpeed;
         [SerializeField] private float maxSpeed;
         [SerializeField] private float ySpawnPos = 11;
     
         public void Start()
         {
             gameManager = GameObject.Find("Game Manager").GetComponent<GameManager>();
         }
     
         public void Awake()
         {
             targetRb = GetComponent<Rigidbody2D>();
             transform.position = RandomSpawnPos();
             targetRb.AddForce((player.transform.position - transform.position) * RandomSpeed());
             targetRb.AddTorque(RandomTorque());
             Time.timeScale = 0.8f;
         }
     
         public void OnTriggerEnter2D(Collider2D other)
         {
             if(other.gameObject.CompareTag("Bullet"))
             {
                 Destroy(gameObject);
                 gameManager.UpdateScore(pointValue); //line that score error directs to
             }
         }
     
         float RandomSpeed()
         { 
             //code that works when there are no if statements, just 1 line:
             //return Random.Range(minSpeed, maxSpeed);
             //replacing that line with the following makes both this & score not work:
             if (gameManager.dif == 0) //easy; line that speed error directs to
               {
                   return Random.Range(minSpeed, maxSpeed);
               }
               else if (gameManager.dif == 1) //med
               {
                   return Random.Range(minSpeed, maxSpeed);
               }
               else //hard
               {
                   return Random.Range(minSpeed, maxSpeed);
               }
         }
     }

relevant GameManager code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using TMPro;
 using UnityEngine.SceneManagement;
 using UnityEngine.UI;
 
 public class GameManager : MonoBehaviour
 {
     public bool isGameActive = true;
     private int score;
     public int lives;
     public int dif;
 
     IEnumerator SpawnTarget()
     {
         while (isGameActive)
         {
             spawnRate = RandomTime();
             yield return new WaitForSeconds(spawnRate);
             int index = Random.Range(0, targetPrefabs.Length);
             Instantiate(targetPrefabs[index]);
         }
     }
 
     public void UpdateScore(int scoreToAdd)
     {
         if(isGameActive)
         score += scoreToAdd;
         scoreText.text = "Score: " + score;
     }
 }