When loading a scene, the previous scene will still be opened

When I’m calling SceneManager.LoadScene(, LoadSceneMode.Additive);
in my 2D project the scene will just be loaded ON TOP of my old scene, meaning that I can still see everything from the old scene. What could be the reason behind it and do I have to provide more information?

you’re using LoadSceneMode.Additive, see:

what you want to do is use LoadSceneMode.Single, see: