Why does my SW-A2 continue to display online on my app even when SW-A1 is powered off?

To conserve power, SW-A2 come into power saving mode after you set up the device.  It will wake up and set off the alarm when it is triggered.  However, if there is no detection of water leakage, SW-A2 only attempts to communicate with SW-A1 every half an hour.  It means the device status of SW-A2 is refreshed on your app every half an hour so it doesn't show offline instantly when SW-A1 is powered off.