Bluetooth API documentation for fuction bt_conn_create_slave_le states:
"The advertising type must be either BT_LE_ADV_DIRECT_IND or BT_LE_ADV_DIRECT_IND_LOW_DUTY."
I think it may be a bit misleading, since it does not appear as one of function argmuents. Maybe we could make it a condition for function argument: const struct bt_le_adv_param *param?