There can be several reasons for this misfunction. First, check your Time Scheduling function. Perhaps, your schedule is cancelled and needs to be reset. The second reason is a low battery charge. In this case, let the robot recharge and repeat cleaning. Finally, Deebot N79S may not clean when it`s scheduled because of the entanglement. Turn your robot off, remove all debris, and try again. If neither of these procedures help, please contact Ecovacs User Service.