When power/battery is removed from the sensor , expected that sensor must go OFFLINE in app

however noticed that sensor is still showing ONLINE , app  is reporting LAST readings of the sensor before power OFF

have done multiple reboot of the H100 where the sensor is registered , but no success it still shows sensor is Online.. 

very strange , was expecting communication loss alarm minimum so that can notice that sensors is removed/powered off and then can take action ON it