https://devzone.nordicsemi.com/f/nordic-q-a/113391/nrf52840-connection-failHi, my device is central device( Central UART ) and I couldn&#39;t get stable pairing with peripheral device with display which provides passkey code. The scenario: 1. From the start, I get a successful pairing (34931_pairing_OK_212.txt 34931_pairing_OK_212en-USTelligent Community 13Wed, 24 Jul 2024 17:28:28 GMThttps://devzone.nordicsemi.com/thread/495495?ContentTypeID=1Wed, 24 Jul 2024 17:28:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b011a473-d9d7-4080-ae5c-2730a8a4daf0Amanda Hsieh<p>Hi,&nbsp;</p> <p>What NCS version are you using?</p> <p>Disconnection reason 0x05 means BLE_HCI_AUTHENTICATION_FAILURE because&nbsp;Pairing is failed. Do you&nbsp;Call&nbsp;<code>settings_load()</code>&nbsp;after initializing Bluetooth so that previous bonds can be restored? See this course&nbsp;<a href="https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/lessons/lesson-5-bluetooth-le-security-fundamentals/topic/blefund-lesson-5-exercise-2/">https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/lessons/lesson-5-bluetooth-le-security-fundamentals/topic/blefund-lesson-5-exercise-2/</a>&nbsp;</p> <p>Regards,<br />Amanda H.</p><div style="clear:both;"></div>