How to stop loading of a scene that's loading using SceneManager.LoadSceneAsync ?

Use-case scenario:

1) Scene is loading using SceneManager.LoadSceneAsync (loading is not complete yet)

2) Suddenly we need to stop the loading of that scene, so we try to use:

 AsyncOperation asyncOperation = SceneManager.UnloadSceneAsync(scenePath);

But the returned asyncOperation is NULL!

Questions:

1) How can we stop loading of a scene?

2) Alternatively, how can we unload a loading scene?

UPDATE1:

Further tests made. Decided to wait for LoadSceneAsync to complete (to avoid the null-return of AsyncOperation), and once it completes, scheduled to start automatic UnloadSceneAsync. That call to UnloadSceneAsync does return non-null AsyncOperation (good part), but the operation (unloading) NEVER finishes (bad part)!

Help Anyone! Is t$$anonymous$$s a Unity bug? Is there are workaround?