Bug potential bug: can't do 2 loadasync consecutively on the timeline

check this out, might be a timeline bug, haven't found a known limitation on that

https://forum.unity.com/threads/2-loadsceneasync-break-in-some-cases-timeline-bug.1076618/

(second async gets lost, doesn't even start actually, might require the first one to complete?)

 

1322239

 

extra repro to isolate vanilla c# from timeline behaviour

Spoiler: code

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.SceneManagement;
5.  
6. public class _TestSceneLoading : MonoBehaviour
7. {
8.     public AsyncDataPipe_SO sceneSO;
9.     public SceneReference scene;
10.     public GameObject activateOnLoading, activateOnActivating;
11.     public float delayBeforeLoad = 0, extraDelayBetweenLoadAndActivate = 0;
12.  
13.     public void Load()
14.     {
15.         StartCoroutine(LoadThenActivateCO());
16.     }
17.  
18.     IEnumerator LoadThenActivateCO()
19.     {
20.         yield return StartCoroutine(LoadCO());
21.         yield return StartCoroutine(ActivateCO());
22.     }
23.  
24.     IEnumerator LoadCO()
25.     {
26.         yield return new WaitForSeconds(delayBeforeLoad);
27.         activateOnLoading.SetActive(true);
28.         activateOnActivating.SetActive(false);
29.         sceneSO.async = SceneManager.LoadSceneAsync(scene, LoadSceneMode.Additive);
30.         sceneSO.async.allowSceneActivation = false;
31.     }
32.  
33.     IEnumerator ActivateCO()
34.     {
35.         yield return new WaitForSeconds(extraDelayBetweenLoadAndActivate);
36.         while (sceneSO.async.progress < 0.9f)
37.             yield return null;
38.         activateOnActivating.SetActive(true);
39.         activateOnLoading.SetActive(false);
40.         yield return null;
41.         sceneSO.async.allowSceneActivation = true;
42.     }
43. }

View attachment 816755
so this button is calling both loadings, each one staggered in time like so
load 1
load 2
activate 2
activate 1

this works flawlessly in the editor and on switch
scene loaded size 300MB