There could be different reasons why a smart light doesn't turn off when the room is darker than the defined threshold. 

  • The light may be located in a room where there is no multisensor installed. In this case, the brightness in this room will be calculated from an average of the brightness in the home. This may not be accurate for a specific room. It is recommended to have a multisensor properly installed in each room having smart lights. 
  • The multisensor detecting brightness may not be installed properly in the room. It may be placed close to a window or in a brighter part of the room which doesn't represent the global brightness of the room. 
  • The light may have been locked by a user interaction within 2 hours. Take a look at How does a smart light react to user interactions from the app?
  • The calibration of the specific smart light may not be accurate. This can be configured at any time from the app under: Devices > Select the right light >  Calibrate