there is an unwritten tip for headlight adjustment which is.
never leave the last setting as you were unscrewing the adjuster screw, As the car runs on the road and vibrates the headlamp etc, the screw can very slowly unscrew, This is why its recommended to always end the adjustment with a slight tension clockwise on the screw.
There is another unwritten tip for headlamps of all cars in the world, their mounting bolts need to be threadlocked to the body (medium threadlock) so they dont vibrate loose. The loosening happens as these are on the very edge of the vehicle the vehicle tends to vibrate like a tuning fork as you pass a bump etc.