The brew unit or capsule plate is soiled.
Clean the brew unit or the capsule plate with a cleaning tablet and hot water.
If the fault persists, also clean the brew unit filter in accordance with the operating instructions.
The coffee machine is filling cups with different volumes of liquid.
Clean the brew unit or the capsule plate with a cleaning tablet and hot water.
If the fault persists, also clean the brew unit filter in accordance with the operating instructions.