Why is this thing poking through and scraping my floor now?

The other day I noticed I was sitting lower than usual and thought my chair was loose or something since the max height stayed the same when I attempted to lift it. It would go down but wouldn’t go to the height I was used to. When I flipped the chair over I noticed this thing shooting through the bottom which also make my wheels not touch the ground and my chair rocks a lot because of it.

Is there any way to fix it? I tried sliding it back through but no luck