If employees are enrolled on the device but are not showing in Jarrison Time, start by confirming if the employee is on the device with templates:
1) Go to Access > Devices.
2) Then select the device and click View Employee.
3) If the employee has templates on the device, confirm the number the employee is enrolled on device with, then click on Import>Employees from device, select the device and click Import.
It may be worth checking the Exceptions log file found in C:\JT-Data\Temp for details regarding the import.