From https://devzone.nordicsemi.com/guides/nrf-connect-sdk-guides/b/software/posts/ncs-dfu, it suggests to call smp_bt_register() for nRF Connect SDK v2.3 or newer. But RTT Viewer shows "<err> bt_gatt: Unable to register handle 0x0016".
The following are log messages of RTT Viewer.
00> *** Booting Zephyr OS build v3.3.99-ncs1 ***
00> Starting Bluetooth Peripheral LBS example before OTA
00> Before calling smp_bt_register()
00> [00:00:00.540,344] <err> bt_gatt: Unable to register handle 0x0016
00> After calling smp_bt_register()
00> Bluetooth initialized
00> Advertising successfully started
Procedures to reproduce this issue are as follows.
1. Unzipping peripheral_lbs.zip to D:\ncs\v2.4.0\nrf\samples\bluetooth folder.
2. cd D:\ncs\v2.4.0\nrf\samples\bluetooth\peripheral_lbs
3. west build -b nrf5340dk_nrf5340_cpuapp
4. west flash
5. Rebooting nRF5340 device and connecting to RTT Viewer.