You have left automatic mode temporarily during cooking.
Do not use the ventilation hood for approx. 5 minutes after selecting a power level manually.
The manually selected fan power level once again matches the automatic power level.
The ventilation hood fan and the cooktop have been switched off for at least 30 seconds. Automatic mode will resume next time the cooktop is switched on.
If the ventilation hood and the cooktop have been switched off for at least 30 seconds after cooking, automatic mode will resume next time the cooktop is switched on.