If your Time Clock is working in every other way, but not recording clocked times, the sim card might need resetting.
To see if the sim is working:
If the device is displaying a ‘No service’ message for either Optus or Telstra (as in the above screenshot):
If reception is restored, try clocking-in to test whether it is now recording in Tanda. If clocking in still doesn’t work from there, try updating the app
If there is still no reception, please email support@tanda.co to order a new sim card.