Answer by Detinator10

I would just have the player's position set to the door when it loads the new scene. So have it use DontDestroyOnLoad and then just run a function after you change scenes that places your character wherever it needs to be. That would be the simplest way to do it. Another thing, if your player is still getting duplicated, you could briefly transition to a blank scene with the player object when your game starts, set the player to not destroy and then load the regular scene. That way there isn't a player game object as part of your scene, only one from a different scene that you never return to