Make sure once again the Seat sensor is activating. (explain to the customer where it is located and how it works)

Many times customers have hard time to understand how to activate the seat sensor

Moving on the seat to adjust your position when activating any of the bidet functions might prevent the bidet from working due to safety reasons

Also, ake sure they touch the spot with naked skin or a really wet towel or paper)  ( coway models drip some water from the nozzle area when the seat sensor is touched correctly) For the other brands the best way is trying the dryer since it exclude water issues)