What are the meanings of the sounds of the Mijia Front Load Washer Dryer Pro 9kg?

Here are the meanings of the sounds of the Mijia Front Load Washer Dryer Pro 9kg when it is running:
  1. When water is filling: As the washing machine fills with water, the water inlet valve operates and produces a "buzzing" sound, which is normal.
  2. During operation: The motor of the washing machine will make a "buzzing" sound during operation, which is normal.
  3. When draining: When the washing machine is draining, the drain pump works and makes a "gulp gulp" sound.
  4. When starting: When the washing machine starts, the door lock closes and makes a "click" sound.