F56 in Miele documentation indicates that the final spin fell below 400 rpm. Support points to excess suds as the user check.
Selected speed and limited speed
The threshold appears in the manufacturer documentation consulted; check whether it applies to the model. A deliberate selection of low revolutions is not by itself the same event as the appliance reporting F56.
Note what speed you selected, the program, and how the laundry finished. If the cycle ran long with rinses or there was visible suds, check detergent amount, concentration, and additives. Final dampness alone does not diagnose a motor or sensor.
Fixing the suds without losing the context
Adjust the next dose to the package directions, water hardness, soil level, and load. Do not add product to rerun a cycle on laundry that may still retain it. The Miele index includes F16 for checking dosing when that alert appears.
If free water is also left behind, report it as a drainage symptom that needs its own diagnostic path. If F56 returns with proper loads and doses, contact service. Do not force a faster spin as a test.
Keep the program and selected revolutions so the technician can distinguish user choice from a detected limitation.