we are using BCM20704 BLE controller which supports BT 4.2 one of our product which is central role for BLE connection. The Peripheral device is BT 5.o and Legacy justwork pairing is used for Bonding with all the key (LTK with EDIV and Rand,IRK,CSRK) distribution on both initiator and responder side. For first time connection to the central is success while on successive re connection it is failed due to MIC check failure after receiving LL_START_ENC_RSP packet from Central(BCM20704) . Though we have tested the peripheral device with few other BLE devices like BlueZ and Android and it is working without any connection issues. Any suggestion .