Hi,..These saeco models have a auto adjusting grinder. If the brewunit is heavy or in other words overloading, the machine will reduce the grinding time lesser to produce less ground coffee.If it senses the brewunit is smooth and light in loading (compressing the grounds), it will increase the grinding until it reaches the optimum dose. So it is important to clean and lubricate the brew unit at all times. Hope it will solve the problem. Good luck.