Please make sure that the WiFi is off and the data on, then follow the steps below.
1. Please press the Phone icon
2. Enter ##72786#. Last # entered will not show on display
3. SCRTN appears briefly.
4. The phone will power off, then power back on.
5. The device will complete the Hands free Activation steps, to program the phone. Will update the PRL, and power off and back on again.
Once the updates are completed, please test the phone and let us know if there's any improvement.