There are always 2 warnings relative to using deprecated OnLevelWasLoaded, and they become annoying:
OnLevelWasLoaded was found on VuforiaBehaviour. This message has been deprecated and will be removed in a later version of Unity. Add a delegate to SceneManager.sceneLoaded instead to get notifications after scene loading has completed.
I was several times trying to hide this message without any success. These warnings is triggered inside readonly scripts.
Please, Vuforia staff, consider to remove deprecated API calls in future updates.