There are a couple of reasons why a subsribers’s location is not correct:
Timing: Look at the time stamp on the location. The Libris takes GPS locations and stores them every 10 minutes, but it only transmits them when an event occurs like a button press or a fall is detected. You can send a message to the device and retrieve the latest location information by clicking on the “Refresh Location” button located in the “Last Recorded location” box.
Type of Signal: Depending on the type of network signal the device has access to, it will determine if the Libris presents a Network fix or a Satellite fix. Satellite fixes are the most accurate and network fixes are based on triangulation between towers so they have a range of accuracy that can be off by a couple blocks. In the “Last Recorded location” box it will identify if the location is a network or satellite fix.