When cleaning, why does the mopping pad not always extend?

The mopping pad may not extend during cleaning in certain scenarios like:

• In Mop Only or Vac and Mop mode, it extends during straight-line cleaning or along edges, but not during zigzagging.
• The mopping pad plate retracts in situations like quick mapping, DEEBOT navigation, crossing rooms, returning for mop washing/charging, avoiding obstacles, moving onto carpets, suspending/ending task and moving machine.