In order to prevent the V.BTTN to disconnect, your application must perform an application verification. Look for the V.BTTN Verification section in the developer start up guide. This should be done within 30 seconds after connection.
Following are steps to connect the V.BTTN to the application:
Enable Bluetooth on the phone.
Press-release V.BTTN button between 10-24 seconds to make visible to the app (discoverable)
Application performs scan for BLE devices and connects to it.
Application performs service discovery
Application sends verification key. This must be done within 30 seconds of connecting to V.BTTN.
Same problem here. I am using Android Nexus 5. My device is getting disconnected after 10 seconds and getting reconnected again with in 2 seconds. Even the official V.ALRT app is giving me the same problem. Please look into it and tell me if I am doing anything wrong.