How do I add A first Person Controller in a scene that generates after play is clicked.

I am In the process of making a maze game, all the videos that I have looked up about first-person controllers say you need to have a scene placed and then add the first person controller, But in my case, the maze is randomly generated and only generates after the play is clicked, and it takes a bit for the maze to completely finish generating. I created a Game manager prefab which I have referencing the Standard assets FPS controller, and I have it dragged into that prefab, but now every time I start the game the First-person character moves by itself across the scene at a really fast pace and it will not stop. I feel like I have tried everything at this point.