You will see a yellow/red exclamation point icon next to the device that is needing attention. If you click on the icon it will indicate the reason. 

Check-in issues
A Yellow exclamation point indicates the device has missed the last check in.
A Red exclamation point indicates the device has missed multiple check in’s.
Last seen date/time: This indicates the device has failed to check in as expected.
Causes: Signal strength/Signal interruption
Resolution: Reset/reposition the device/Make sure wi-fi connection is stable or your sensor is able to reach the access point.
The device’s battery is getting low
Resolution: change batteries
Please note: It can take 24 hours for the app to update the battery level after changing batteries.

Sensor Check-in/Reporting:
Sensors check-in to the SmartBase every 24 hours and report the sensor status. SmartBase collects this information and reports it to the cloud once a day.

• Sensor battery level
• The temperature of the SmartBase and the Water leak/Temperature sensors
• Wireless signal strength