Windows 10 IoT Raspberry Pi 2 Bluetooth to Windows Phone 8.1 - Element Not Found

Environment:

1. I have a Windows Phone 8.1 Lumina
2. Raspberry PI 2, CSR Bluetooth Dongle
3. Windows 10 IOT Core 10.0.14322.1000

I create a windows phone 8.1 app and windows 10 iot app for raspberry pi to send and receive messages using Bluetooth. But no success until now!

I am able to go to web interface for Pi and pair Windows phone successfully. On the phone I am able to deduct the Pi's dongle and connect to it.

But from the app when I tried to connect to it to send and receive messages I get the following error

System.Exception: Element not found. (Exception from HRESULT: 0x80070490)

I have tried various suggestions

1. Adding capabilities to the phone's manifest (Proximity, bluetooth, etc)

   <Capabilities>
   <Capability Name="internetClientServer" />
   <DeviceCapability Name="proximity" />
   <m2:DeviceCapability Name="bluetooth.rfcomm">
     <m2:Device Id="any">
       <m2:Function Type="serviceId:00001101-0000-1000-8000-00805F9B34FB"/>
     </m2:Device>
   </m2:DeviceCapability>
   

2. Tried various suggestions

Link 1

Link 2