How to detect binding information lost?

Hi all,

I'm using nrf51822 and ble_app_multirole_lesc example on SDK 12.3.

When I connect with "nrf connect" Android application for the first time, the bind is established and the communication is secure.

After that, I deleted the bond information from the mobile phone and I tried to reconnect again, nRF accepts the connection and calls "PM_EVT_PEER_DATA_UPDATE_SUCCEEDED" event.

1-How can this happen?

2-Is there an event called (nRF side) to detect that the mobile has lost the binding information?

Best regards.