That’s your steering stem? mine looks totally different. It has the collapsible steering stem so that you could lower the handlebars to put it in your car. It’s loose in the sleeve that slides over the steering stem
Mine is foldable too, My handle bars used to turn back and forth until I tightened the center bolt with wedge that goes into the frame. You might try to shim w/ alum strips cut out of a coke can, I use them to shim a loose exhaust connection also.