Hello.
I am experiencing an issue where Mesh communication fails after connecting to the SMP Service in the Bluetooth Mesh DFU Distributor sample.
Environment:
- NCS Version: v3.2.3
- Hardware: nRF54L15DK
- Sample: Bluetooth Mesh: Device Firmware Update (DFU) distributor
- Configuration:
`overlay-smp-bt-auth.conf`is included in the build to enable authentication.
Steps to Reproduce:
- Flash the DFU Distributor sample to the nRF54L15DK.
- Provision the DK using the nRF Mesh mobile app.
- Initiate a connection to the SMP Service using the nRF Connect mobile app.
- When prompted for pairing, enter the passkey and complete the connection.

- Switch back to the nRF Mesh app and attempt any Mesh communication.
- The error
"Failed to send proxy message (err -22)"occurs.
Serial Terminal Log:
*** Booting MCUboot v2.3.0-dev-252d7bbd7909 ***
*** Using nRF Connect SDK v3.2.3-6f8485d2890d ***
*** Using Zephyr OS v4.2.99-c4c75f71e709 ***
I: Starting bootloader
I: Primary image: magic=good, swap_type=0x1, copy_done=0x3, image_ok=0x1
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: primary slot
I: Image index: 0, Swap type: none
I: Bootloader chainload address offset: 0xe000
I: Image version: v1.0.0
I: Jumping to the first image slot
*** Booting Mesh DFU Distributor v3.2.3-59f00e1776b2 ***
*** Using nRF Connect SDK v3.2.3-6f8485d2890d ***
*** Using Zephyr OS v4.2.99-c4c75f71e709 ***
Initializing...
Current image version: 1.0.0+0
[00:00:00.023,349] <inf> fs_zms: 2 Sectors of 4096 bytes
[00:00:00.023,358] <inf> fs_zms: alloc wra: 0, fc0
[00:00:00.023,365] <inf> fs_zms: data wra: 0, 0
[00:00:00.025,621] <inf> bt_sdc_hci_driver: SoftDevice Controller build revision:
9b 6b 70 25 37 79 e5 f2 f6 cb 16 a5 8b b9 9a 13 |.kp%7y.. ........
a8 05 75 dc |..u.
[00:00:00.026,730] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.026,748] <inf> bt_hci_core: HW Variant: nRF54Lx (0x0005)
[00:00:00.026,761] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 155.28779 Build 3849926437
[00:00:00.026,878] <inf> bt_hci_core: No ID address. App must call settings_load()
Bluetooth initialized
[00:00:00.028,646] <inf> bt_hci_core: HCI transport: SDC
[00:00:00.028,694] <inf> bt_hci_core: Identity: EB:DA:FA:1C:B3:05 (random)
[00:00:00.028,711] <inf> bt_hci_core: HCI: version 6.2 (0x10) revision 0x306a, manufacturer 0x0059
[00:00:00.028,726] <inf> bt_hci_core: LMP: version 6.2 (0x10) subver 0x306a
[00:00:00.038,966] <inf> bt_mesh_provisionee: Device UUID: 8ef20279-6f06-4103-b10d-fd8690f9befc
Mesh initialized
Created a new identity for SMP: 1
[00:00:00.042,016] <dbg> bt_mesh_dfu_srv: bt_mesh_dfu_srv_applied: Wrong state
[00:00:29.776,807] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
[00:00:32.089,368] <inf> bt_mesh_main: Primary Element: 0x0003
[00:00:32.089,384] <dbg> bt_mesh_main: bt_mesh_provision: net_idx 0x0000 flags 0x00 iv_index 0x0000
[00:00:32.178,808] <dbg> bt_mesh_health_srv: attention_off:
[00:00:33.181,896] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
[00:00:34.143,070] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00
[00:00:34.143,080] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0
[00:00:34.443,570] <dbg> bt_mesh_cfg_srv: default_ttl_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 0:
Connected to SMP service: err 0 id 1
[00:00:51.512,538] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a
Please enter passkey (670831) on 5A:47:4F:F6:2A:14 (random)
Pairing completed: 38:53:9C:AB:F0:B7 (public), bonded: 1
[00:02:04.790,809] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00
[00:02:04.790,823] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0
[00:02:04.836,494] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:04.897,007] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:04.957,333] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:05.017,691] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:05.518,072] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:05.578,387] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:05.638,764] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:05.699,091] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.199,627] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.260,103] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.320,429] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.380,826] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.881,179] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:06.941,526] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:07.001,847] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:07.062,165] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:07.562,265] <err> bt_mesh_transport: Ran out of retransmit without progress attempts
[00:02:09.381,174] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00
[00:02:09.381,189] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0
[00:02:09.407,837] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:09.468,153] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:09.528,468] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:09.588,785] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.089,142] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.149,579] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.210,023] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.270,423] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.770,778] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.831,094] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.891,414] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:10.951,733] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:11.452,086] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:11.512,408] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:11.572,726] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:11.633,265] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:12.133,367] <err> bt_mesh_transport: Ran out of retransmit without progress attempts
[00:02:18.441,334] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00
[00:02:18.441,349] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0
[00:02:18.461,993] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:18.522,326] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:18.582,646] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:18.643,001] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.143,383] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.203,704] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.264,024] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.324,400] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.824,764] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.885,076] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:19.945,398] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:20.005,715] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:20.506,104] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:20.566,606] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:20.626,934] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:20.687,252] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:21.187,319] <err> bt_mesh_transport: Ran out of retransmit without progress attempts
[00:02:36.501,977] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00
[00:02:36.501,992] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0
[00:02:36.543,777] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:36.604,186] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:36.664,499] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:36.724,823] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.225,206] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.285,559] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.345,878] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.406,360] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.906,855] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:37.967,293] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.027,770] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.088,282] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.588,630] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.648,950] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.709,270] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:38.769,587] <err> bt_mesh_proxy: Failed to send proxy message (err -22)
[00:02:39.269,687] <err> bt_mesh_transport: Ran out of retransmit without progress attempts
Observations: After step 6, Mesh communication could be resumed by performing any of the following:
- Rebooting the DK.
- Restarting the nRF Mesh app.
- Disconnecting the Mesh Proxy Service in the nRF Mesh app and then reconnecting.
Serial Terminal Log:
[00:02:38.769,587] <err> bt_mesh_proxy: Failed to send proxy message (err -22) [00:02:39.269,687] <err> bt_mesh_transport: Ran out of retransmit without progress attempts [00:06:03.365,912] <wrn> bt_l2cap: Ignoring data for unknown channel ID 0x003a [00:06:16.687,531] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 1: 00 [00:06:16.687,546] <dbg> bt_mesh_cfg_srv: dev_comp_data_get: Preparing Composition data page 0 [00:06:17.017,734] <dbg> bt_mesh_cfg_srv: default_ttl_get: net_idx 0x0000 app_idx 0xfffe src 0x0001 len 0:
The issue does NOT occur in the following cases:
- If I connect to the Mesh Proxy Service advertisement instead of the SMP Service in step 3.
- If authentication is disabled (i.e., when
`overlay-smp-bt-auth.conf`is not included in the build).
Since this issue is reproducible using the standard sample program and official apps available on the App Store, it should be easy to verify on your end.
Thank you for your time and assistance.
Best regards,
a.da