bleak pair failed with protection_level 1

[snowuyl]

• bleak version: v0.20.2
• Python version: v3.11.4
• Operating System: Windows 11

Description

I added the following code in sample program uart_service.py for pairing with Nordic nRF5340 device.

async with BleakClient(device, disconnected_callback=handle_disconnect) as client:
        await client.start_notify(UART_TX_CHAR_UUID, handle_rx)
        paired = await client.pair(protection_level=1)
        print(f"Paired: {paired}")

Logs

Log messages of Windows 11 command prompt is as follows.

D:\workspace_Python\bleak\examples>python3 uart_service.py
Device was disconnected, goodbye.

Log messages of RTT Viewer is as follows.

00> *** Booting Zephyr OS build v3.2.99-ncs2 ***
00> btInit() e
00> btInit() x
00> _btReady(0) e
00> Bluetooth initialized
00> _btReady(0) x
00> connected() e
00> Connected D8:F8:83:9F:72:1A (public)
00> _gCurrentConn=0x20001568
00> state = connect
00> connected() x
00> _gBtNusMtu=244
00> BT NUS thread starts running
00> [00:00:16.780,761] <wrn> btnus: NUS send timeout
00> Security failed: D8:F8:83:9F:72:1A (public) level 1 err 9Pairing failed conn: D8:F8:83:9F:72:1A (public), reason 9state = disconnect
00> Disconnected: D8:F8:83:9F:72:1A (public) (reason 19)