Then i would say the cluch is slipping, cant remember how it looks on a 1570 or whether it can be fixed by cleaning but normaly so.
way to tell is the 1570 is a direct drive seconds, the drive for the seconds comes direct from the 3rd wheel in the movement, the hours and min run via a clutch mech that alow you to set the time, if the clutch is stlipping then there is no drive to the hands except the seconds (which does not run via the clutch), the very easy time setting is like putting a car in gear and being able to push it down the street with out the engine turning over.