I created an Android app based on your Nrf UART app ver 1.0, which works fine on Android 4.4 and 5.0, but not 6.0. On 6.0, it cannot find the ble device. But I downloaded nRF UART v2.0 app from google play store recently, and it does find the BLE device on Android 6.0 device, so I am wondering if I get the source code for UART 2.0 app and check what is the difference causing the problem? thanks