Yes - its the nature of mechanical movements - they are affected a lot more by gravity.
One that has been regulated extremely well. and serviced, will show less variation - but they will still all do it.
There was an advisory issued by Rolex what said to make it gain leave it face up, to lose a bit leave it crown down; and to lose a bit more leave it crown up - but this is a generalisation and different movements will behave differently.