问为什么这个重装武器的协程程序不能工作？

EN

using UnityEngine;
using System.Collections;
using TMPro;

public class GunScript_SB : MonoBehaviour
{
    public float damage = 10f;
    public float range = 100f;
    public float impactForce = 30f;
    public float fireRate = 15f;

    public float maxAmmo = 10;
    private float currentAmmo;
    public float reloadTime = 3f;
    private bool isReloading = false;

    public Camera fpsCam;
    public ParticleSystem muzzleFlash;
    public GameObject impactEffect;
    public TextMeshProUGUI ammunitionDisplay;

    private float nextTimeToFire = 0;

    void Start()
    {
        currentAmmo = maxAmmo;
    }

    void onEnable()
    {
        isReloading = false;
        AmmoDisplay();
    }

    // Update is called once per frame
    void Update()
    {
        if (isReloading)
            return;

        if (currentAmmo <= 0)
        {
            StartCoroutine(Reload());
            return;
        }

        if (Input.GetButtonDown("Fire1") && Time.time >= nextTimeToFire)
        {
            nextTimeToFire = Time.time + 1f / fireRate;
            Shoot();
        }

        if (ammunitionDisplay != null)
        {
            AmmoDisplay();
        }

        if (Input.GetKeyDown(KeyCode.R) && currentAmmo < maxAmmo)
        {
            StartCoroutine(Reload());
        }
    }

    public IEnumerator Reload()
    {
        isReloading = true;
        Debug.Log("Reloading...");

        yield return new WaitForSeconds(reloadTime);

        currentAmmo = maxAmmo;
        isReloading = false;
    }

    void Shoot()
    {
        muzzleFlash.Play();
        currentAmmo--;

        RaycastHit hit;
        if (Physics.Raycast(fpsCam.transform.position, fpsCam.transform.forward, out hit, range))
        {
            Debug.Log(hit.transform.name);

            Target target = hit.transform.GetComponent<Target>();
            if (target != null)
            {
                target.TakeDamage(damage);
            }

            if (hit.rigidbody != null)
            {
                hit.rigidbody.AddForce(-hit.normal * impactForce);
            }

            GameObject impactGO = Instantiate(impactEffect, hit.point, Quaternion.LookRotation(hit.normal));
            Destroy(impactGO, 1f);
        }
    }

    void AmmoDisplay()
    {
        ammunitionDisplay.SetText(currentAmmo + " / " + maxAmmo);
    }
}