Method doesn't get implemented after subscribing to Func

I have the following script which contains a func that takes in a Vector2 as an argument and returns IEnumerator

 using System;
 using System.Collections;
 using UnityEngine;
   
 public class Weapon : MonoBehaviour
 {
 public static event Func<Vector2, IEnumerator> OnFire;
   
 private void OnMouseDown()
 {
     Fire();
 }
  
 private void Fire()
 {
     Vector2 mousePosition = new Vector2(Camera.main.ScreenToWorldPoint(Input.mousePosition).x, Camera.main.ScreenToWorldPoint(Input.mousePosition).y);
   
     if (OnFire != null)
     {
         OnFire.Invoke(mousePosition);
     }
 }
 }

In my other script, I have a Coroutine that subscribes to that method

  using System;
  using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
     
  public class Bullet : MonoBehaviour
  {

 private void Start()
 {
     Weapon.OnFire += ShootAt;
 }
  
 private IEnumerator ShootAt(Vector2 target)
 {  
     yield return new WaitForSeconds(.5f);
       print("Shot at " + target);
 }   
        
 private void OnDestroy()
 {
     Weapon.OnFire -= ShootAt;
 }
  
 }

But the ShootAt method in my Bullet script never gets called. It's as if it's not even subscribing to the event, or the event isn't even being invoked. I don't have any compile errors.