@pixiestyk ,Joy, Open truck lid and recheck all fasteners for tightness and not missing. There may have been a gasket on the spoiler that has deteriorated(foam tape) allowing spoiler to be a little loose. In this case, it would require the removal of the spoiler and reapplication of foam. Links below may help you see where the screw/fasteners, foam gasket,etc are and also shows removal and installation of spoiler. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
https://www.youtube.com/watch?v=UxqvDv4QzmM
https://www.youtube.com/watch?v=Md1CDucgbOE