My S5 Max robot is located in the bedroom. I am very sensitive to light and need to sleep in a totally dark room. DND works great most of the time. But on several occasions, in the middle of the night, both buttons have started flashing very brightly together for about 20 seconds, and then it stops. The lights are bright enough to wake me up. When it happens, it is always around 2 AM or 3 AM. I would suspect that it was receiving a firmware update but those don't happen automatically. Regardless of the reason why the robot decides to flash its lights brightly, that needs to be fixed so that it respects DND mode.