Regarding BLE device connection problem with android apk


We are using nRF51DK for our development, we have developed Android app for Android smart phone.

When the Nordic BLE device advertising we are trying for BLE connection with android apk. But most of the times it gets failed to connect.Rarely it get connected after so many trials.

We are using BLE_APP_UART code from SDK12.3.0.

Please suggest solution for  this problem.

Thanks & regards,