Addforce not moving target (2D)

I'm having this issue inside of FixedUpdate where AddForce doesn't do anything to its target. I'm pretty new to C# so I might be missing something but when I compared this method to the other times I use AddForce, there seems to be no difference. I don't think any of those scripts are interfering with this one either. Does anyone have a solution? Here's my whole script in case you need it.

 public int damage;
 private Rigidbody2D playerRB;
 private Transform pos;
 private bool isFlipped;
 public bool pushing = false;
 public float pushTimer = .15f;
 private void Awake()
 {
     playerRB = GameObject.Find("GunHopGuy").GetComponent<Rigidbody2D>();
     pos = gameObject.GetComponent<Transform>();
 }
 void Start()
 {
     if (gameObject.tag == "Boss")
     {
         damage = 10;
     }
     else
     {
         damage = 5;
     }
 }

 // Update is called once per frame
 void Update()
 {
     // Flipping
     if (pos.rotation.eulerAngles.y == 180 | pos.rotation.eulerAngles.y == -180)
     {
         isFlipped = true;
     }
     else if (pos.rotation.eulerAngles.y == 0)
     {
         isFlipped = false;
     }
     // Pushing and push timer
     if (pushTimer <= 0)
     {
         pushing = false;
         pushTimer = .15f;
     }

 }

     private void FixedUpdate()
 {
     // Knockback
     if (pushing == true)
     {
         if (isFlipped == true)
         {
             playerRB.AddForce(new Vector2(12f, 0f), ForceMode2D.Impulse);
         }
         else if (isFlipped == false)
         {
             playerRB.AddForce(new Vector2(-12f, 0f), ForceMode2D.Impulse);
         }

         pushTimer -= Time.deltaTime;
     }


 }

 private void OnCollisionEnter2D(Collision2D collision)
 {
     if (collision.gameObject.tag == "Player")
     {
         pushTimer = .15f;
         pushing = true;
         // Damage
         if (collision.gameObject.TryGetComponent<Health>(out Health player))
         {
             player.TakeDamage(damage);
         }
         // Set "pushing" to true

     }


 }