Bug caused by Singleton Pattern

This is my audio manager script(singleton)

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class AudioManager : MonoBehaviour {
 
     private static AudioManager _instance;
 
     public static AudioManager Instance {
         get { 
             if (_instance == null) {
                 Debug.Log ("No AudioManager gameobject was found");
             }
         
             return _instance;
         }
     }
 
     void Awake(){
         _instance = this;
     }
 
     void Start(){
     }
 
     public AudioSource AddAudio(GameObject targetGameObject, AudioClip clip, bool loop, bool playOnAwake, float volume){
         AudioSource newAudio = targetGameObject.AddComponent<AudioSource> ();
         newAudio.clip = clip;
         newAudio.loop = loop;
         newAudio.playOnAwake = playOnAwake;
         newAudio.volume = volume;
 
         return newAudio;
     }
 }

and this is my Shoot script(attached to enemy and player object) that calls the singleton

     void Awake(){
         shootAudio = AudioManager.Instance.AddAudio (this.gameObject, shootClip, loop, playOnAwake, audioVolume);
     }
 
        void ShootStuff(){
              shootAudio.Play();
        }

I set up up this way so that if the ShootScript(or any other script) requires another sound clip to be played, i can just create a new audio source in the script, reference it to the instance of AudioManager's AddAudio function, and a AudioSource component will be created automatically.

The problem arises when i clone the Enemy prefab, the ShootScriptComponent on the cloned Enemy automatically disables when i run the game. Why is it that the Player object that has the same shootScript attached works fine but not for the cloned Enemy, and how should i fix it??? Thanks