I believe this is because of the commit here: https://github.com/muckSponge/UnityAsync/commit/e01e2dc39084e4b5181dcef98344291ea3d5ddc3#diff-86c1eb8e1ae625825c97d335eaea9712 `if(!Application.isEditor) // DontDestroyOnLoad can not be called in editor mode DontDestroyOnLoad(Instance);` When loading a new scene, the AsyncManager instance is destroyed preventing any Await calls to complete. DontDestroyOnLoad does work in Editor. So not following the reasoning behind the change.