nRF52840 DK, Zigbee Light Switch, BUS FAILURE when using a template project (no changes)

Question

Hi, I am using nRF52840DK SDK 2.5.0 for testing Zigbee. I have three boards of this type, for the coordinator, router and end device. 
 For testing I use the end device I use the Zigbee Light Switch project and there is one very big problem with it, it cannot be rebooted, any attempt to reboot results in BUS FAULT: E: ***** BUS FAULT ***** E: Imprecise data bus error E: r0/a1: 0x00005e53 r1/a2: 0x2003fff8 r2/a3: 0x00000001 E: r3/a4: 0x00005e49 r12/ip: 0x150b000a r14/lr: 0x00011dab E: xpsr: 0x81000000 E: s[ 0]: 0x00058464 s[ 1]: 0x00000000 s[ 2]: 0x000584cc s[ 3]: 0x0000000 0 E: s[ 4]: 0x00000000 s[ 5]: 0x000135e3 s[ 6]: 0x000135cd s[ 7]: 0x0002cd1 3 E: s[ 8]: 0x2000cdb4 s[ 9]: 0x0002cd19 s[10]: 0x00000000 s[11]: 0x0002cd2 7 E: s[12]: 0x20003c38 s[13]: 0x00011b4f s[14]: 0x0002cd19 s[15]: 0x00012d0 1 E: fpscr: 0xaaaaaaaa E: Faulting instruction address (r15/pc): 0x00011dac 
 The only way to use this firmware is to constantly burn it again, in this form it allows you to test at least something. 
 I tested this project on 3 similar boards, the result is the same. On the SDK version 2.6.0 the project does not build at all. #
# Copyright (c) 2020 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

CONFIG_NCS_SAMPLES_DEFAULTS=y

CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_SERIAL=y
CONFIG_GPIO=y

# Make sure printk is not printing to the UART console
CONFIG_CONSOLE=y
#CONFIG_UART_CONSOLE=y

CONFIG_HEAP_MEM_POOL_SIZE=2048

CONFIG_ZIGBEE=y
CONFIG_ZIGBEE_APP_UTILS=y
CONFIG_ZIGBEE_ROLE_END_DEVICE=y

# Enable DK LED and Buttons library
CONFIG_DK_LIBRARY=y

# This example requires more workqueue stack
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

# Enable API for powering down unused RAM parts
CONFIG_RAM_POWER_DOWN_LIBRARY=y

# Networking
CONFIG_NET_IPV6=n
CONFIG_NET_IP_ADDR_CHECK=n
CONFIG_NET_UDP=n

CONFIG_CRYPTO=y
CONFIG_MBEDTLS=y
CONFIG_MBEDTLS_AES_C=y
CONFIG_MBEDTLS_CIPHER_MODE_CTR=y
CONFIG_MBEDTLS_CMAC_C=y

CONFIG_NORDIC_SECURITY_BACKEND=y

# Custom (NUS)
# Включение поддержки Bluetooth
CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_NUS=y

# Настройка устройства
CONFIG_BT_DEVICE_NAME="nRF52840 Light Switch"

##############################

# Включаем логи для Bluetooth
CONFIG_BT_DEBUG_LOG=y
 
 I am also attaching the current version of prj.conf, the configuration has already been partially changed to allow sending commands via nRF Toolbox.