Scene Manager and Keeping Objects when Loading/Unloading + Gameogject.SetActive not working:(

Hey! I'm in a bit a pickle. I'll tell you what I'm trying to achieve first. It's a first-person "fighter game" where you're interacting with robots (one at a time) placed in different environments with separate HDRI maps. There should be a "base scene" that never unloads - containing its own camera, controller, score-manager, and the robots themselves (one robot per scene). If a robot was punched and fell down, it would trigger a new scene to appear containing a new HDRI map and new destroyable objects. The falling robot would land onto a pile of other robots in a separate display that's still part of the "base scene" and would stay there. The falling robot would trigger a new robot to appear (Set.Active) in the "base scene" as well. This is something that I was experimenting with, but couldn't figure out. I got the scene loading and unloading part working, but I can't seem to set new robots active. This script is for the trigger that robots falls through:

 using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     using UnityEngine.SceneManagement;
         public class acivateRobot : MonoBehaviour {
         public GameObject RobotKyle;
         private void Start()
         {
            RobotKyle = GameObject.FindGameObjectWithTag("Robot3");
             RobotKyle.SetActive(false);
         }
         private void OnTriggerEnter(Collider other)
         {
             if(other.CompareTag("Robot"))
             RobotKyle.SetActive(true);
             this.gameObject.SetActive(true);
             Debug.Log("Kyle is active");
           }
     }

In addition to the script above, I'm running this manager script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 public class AnyManager : MonoBehaviour {
     public static AnyManager anyManager;
     bool gameStart;
     void Awake ()
     {
         if(!gameStart)
         {
             anyManager = this;
             SceneManager.LoadSceneAsync(1, LoadSceneMode.Additive);
             gameStart = true;
         }        
     }
     public void UnloadScene(int SceneNumber)
     {
         StartCoroutine(Unload(SceneNumber));
     }
     IEnumerator Unload(int SceneNumber)
     {
        yield return null;
         SceneManager.UnloadSceneAsync(SceneNumber);
     }
 }

Ans two simple scripts to load and unload scenes if a robot were to fall through another trigger(attached to separate scenes).:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 
 public class Load : MonoBehaviour
 {
     public int SceneNumber;
     bool loaded;
     private void OnTriggerEnter(Collider other)
     {
         if (!loaded)
         {
             SceneManager.LoadSceneAsync(SceneNumber, LoadSceneMode.Additive);
             loaded = true;
         }
     }
 }
 
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 public class Unload : MonoBehaviour 
 {
     public int SceneNumber;
     bool unloaded;
     private void OnTriggerEnter(Collider other)
     {
         if (!unloaded)  
         unloaded = true;
         AnyManager.anyManager.UnloadScene(SceneNumber);
     }
 }
 

I would greatly appreciate your help! Perhaps there's a better way to do this? Thanks!