The bt_mgmt_init function returns an error.

[Junichi]

I am creating a program using the nRF5340 Audio sample source.
I am debugging using VSCODE instead of a script.

The bt_mgmt_init function returns error code -11.

Tracing it, I find that -11 is returned at err = bt_dev.drv->open(); in hci_core.c.
Tracing it further, I find that -11 is returned at ret = arch_swap(key); in kswap.h.

When debugging, sometimes the function no longer gives an error, and once it no longer gives an error, it works normally for a while, but when I do something else and try to run it again, the error comes back.

I think the bt_mgmt_init function is a Bluetooth initialization function, so I haven't made any changes to this part.

What could the cause be?

[Junichi]

Additional information.

I have two nRF5340 Audio DK boards, two MDBT53-DB boards made by RAYTAC, and two customer boards.

I am developing software that uses the source code of nRF5340 Audio in VSCODE.

With the same source code, the bt_mgmt_init(); function does not return an error when using the MDBT53-DB board, but an error code is returned when using the customer board.

The customer board has a RAYTAC MDBT53-1M mounted on it.

The difference is that the customer board does not have coils mounted on the DCCD, DCCH, or DCC terminals, so it cannot operate in DCDC mode.

However, even when the MDBT53-1M is set to LDO mode, the mgmt_init(); function does not return an error.

What could this be?