power window goes down on its own
Did you have to pay extra for that feature
And now for a halfway constructive response. If you park it outside it’s possible water got in the door and shorted the window controller. It’s been known to happen with other GM vehicles.
Maybe it’s a hint that it’s time for a new air freshener?
Is this happening when you are not in the vehicle? If so, check your pockets/purse and make sure nothing’s pressing on the unlock button. Some cars have a feature that lowers the windows when you long-press the unlock button, for ventilation on a hot day.