During the development of Nordic 52810, after the softdevice is re written, when nrfconnect for Mobile Connect is used, the connection fails, and the mobile phone displays peer removed pairing information. Device side log information:

< info> peer_ manager_ handler: Connection security failed: role: Peripheral, conn_ handle: 0x0, procedure: Encryption, error: 4102

Solution: in the Bluetooth settings of the mobile phone, find the device to be connected, select “ignore this device”, and re connect with nrfconnect. Success!