When the device is shut down or when the internet connection is temporarily lost, does the system store the check in and check out times? And upon return of power or connection, do these get uploaded?
Yes - when the device is offline but powered on, users can still check in and out. Once the internet connection is restored, the service will check and grab all the logs it missed while the power or internet was out.
In some cases, biometric logs may not sync automatically when the power or internet connection returns. To fix this, you can restart the fetcher by following the steps in this article - How Do I Restart the Biometric Logs Fetcher?