Some things that carry a bit of load can come loose so it’s simply a matter of tightening up the screws ….. But often if the screw is fitted to hollow walls or doors the screw hole has widened and lost it’s grip.
The best solution is to get some RUBBER WELL NUTS (plenty on eBay) – plus some screws to fit – and drill the screw hole to fit the new nuts.
As the screw is tightened the rubber expands behind the panel providing a good solid right fit.