Cannot connect using connection manager

[Adamcs]

Hi, 

I'm trying to use the connection manager in my application, but it never connects or shows any events. I've tried using the https_client sample as well, but that gives me the same result.

There's an existing thread which mirrors the exact same issue I'm experiencing.  NRF9160 Connection Manager with LTE 

I'm able to connect to an LTE network manually like so:

nrf_modem_lib_init();
modem_info_init();
lte_lc_register_handler(lte_event_handler);
lte_lc_connect_async(lte_event_handler);

I'm testing on SDK v3.2.1 with nRF9160dk. This is the log output I'm getting from the https_client sample:

HTTPS client sample started
[00:00:00.386,016] <dbg> net_mgmt: net_mgmt_add_event_callback: (main): Adding event callback 0x2000d330
[00:00:00.386,077] <dbg> net_mgmt: net_mgmt_add_event_callback: (main): Adding event callback 0x2000d318
Bringing network interface up
[00:00:00.386,138] <dbg> net_if: net_if_up: (main): iface 1 (0x2000d288)
[00:00:00.386,199] <dbg> net_mgmt: net_mgmt_event_notify_with_info: (main): Notifying Event layer 0x2 code 0x1 type 0x8
[00:00:00.386,322] <dbg> net_mgmt: mgmt_event_work_handler: (net_mgmt): Handling events, forwarding it relevantly
[00:00:00.386,383] <dbg> net_mgmt: mgmt_run_slist_callbacks: (net_mgmt): Event layer 0x2 code 0x1 cmd 0x8
[00:00:00.386,444] <dbg> net_mgmt: mgmt_run_slist_callbacks: (net_mgmt): Running callback 0x2000e198 : 0x1d689
[00:00:00.386,627] <dbg> net_if: update_operational_state: (main): iface 1 (0x2000d288), oper state UP admin UP carrier ON dormant OFF
[00:00:00.386,688] <dbg> net_mgmt: net_mgmt_event_notify_with_info: (main): Notifying Event layer 0x2 code 0x1 type 0x2
[00:00:00.386,779] <dbg> net_mgmt: mgmt_event_work_handler: (net_mgmt): Handling events, forwarding it relevantly
[00:00:00.386,840] <dbg> net_mgmt: mgmt_run_slist_callbacks: (net_mgmt): Event layer 0x2 code 0x1 cmd 0x2
[00:00:00.386,901] <dbg> net_mgmt: mgmt_run_slist_callbacks: (net_mgmt): Running callback 0x2000e168 : 0x1d1ed
[00:00:00.386,962] <dbg> conn_mgr: conn_mgr_iface_events_handler: (net_mgmt): Iface event 0xd010000000000002 received on iface 1 (0x2000d288)
[00:00:00.386,993] <dbg> conn_mgr: conn_mgr_iface_events_handler: (net_mgmt): Iface index 0
Provisioning certificate
Connecting to the network

Is there something extra that needs to be done which the sample doesn't show? I recall being able to use the connection manager successfully in an earlier SDK version, but having trouble remembering now. Is anyone able to connect using the sample, or suggest what could be going wrong?

Thanks

[Øyvind]

Hello,

What happens after "Connecting to the network"? Are you able to connect to the network at all? How long did you leave it running? What SIM are you using? What modem FW are you running in the nRF9160? Will need to try to replicate on my side. 

I'm able to connect to an LTE network manually like so:

Could you share logs from a successful connection?

Kind regards,
Øyvind

[Adamcs]

Øyvind said:

What happens after "Connecting to the network"? Are you able to connect to the network at all? How long did you leave it running?

No, I've never seen anything output beyond that line in the tested sample. I believe I've tried waiting at least 10-30 minutes, but I can try letting it run overnight just in case.

Øyvind said:

What SIM are you using?

I'm using an iBASIS SIM card, like what had come with the nRF9160dk. I'll try it out on one from a different provider.

Øyvind said:

What modem FW are you running in the nRF9160?

mfw_nrf9160_1.3.7

---

Here's the request output, from a modem callbacks sample.

*** Booting nRF Connect SDK v3.2.1-d8887f6f32df ***
*** Using Zephyr OS v4.2.99-ec78104f1569 ***
[00:00:00.464,904] <dbg> os: setup_thread_stack: stack 0x2000dd50 for thread 0x2000c930: obj_size=1280 buf_start=0x2000dd50  buf_size 1280 stack_ptr=0x2000e250
[00:00:00.480,102] <dbg> os: setup_thread_stack: stack 0x2000e250 for thread 0x2000ca40: obj_size=1280 buf_start=0x2000e250  buf_size 1280 stack_ptr=0x2000e750
[00:00:00.495,269] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000c7ec, count: 1, orig prio: 0
[00:00:00.505,737] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:00.514,129] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:00.523,925] <dbg> os: k_sched_unlock: scheduler unlocked (0x2000cbe0:0)
[00:00:00.761,535] <dbg> nrf_modem: nrf_modem_lib_init: Modem init callback: 0xe2e1
[00:00:00.769,989] <dbg> nrf_modem: nrf_modem_lib_init: Modem init callback: 0x10cd5
[00:00:00.778,533] <dbg> modem_antenna: set_antenna_configuration: Setting configuration: AT%XMAGPIO=1,0,0,1,1,1574,1577
[00:00:00.790,313] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:00.807,434] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:00.815,795] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:00.825,561] <dbg> modem_antenna: set_antenna_configuration: Setting configuration: AT%XCOEX0=1,1,1565,1586
[00:00:00.836,700] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:00.853,820] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:00.862,152] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:00.871,948] <dbg> nrf_modem: nrf_modem_lib_init: Modem init callback: 0x84e9
> Initialized with value 0
[00:00:00.882,904] <dbg> nrf_modem: nrf_modem_lib_init: Modem init callback: 0xf2a9
[00:00:00.891,387] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:00.908,477] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:00.916,839] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:00.926,635] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:00.945,373] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:00.953,735] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:00.963,531] <dbg> lte_lc: xsystemmode_mode_set: System mode set to 1, preference 0
[00:00:00.972,564] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:00.989,746] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:00.998,077] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.014,251] <dbg> lte_lc: dns_fallback_set: Fallback DNS address successfully set to 1.1.1.1
[00:00:01.024,078] <dbg> lte_lc: lte_lc_connect_async: Connecting asynchronously
[00:00:01.032,287] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000c7ec, count: 1, orig prio: 0
[00:00:01.042,846] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:01.051,208] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:01.061,004] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:01.078,125] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.086,486] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.096,282] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:01.113,372] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.121,704] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.131,530] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:01.148,590] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.156,951] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.166,748] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:01.183,837] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.192,169] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.201,995] <dbg> os: z_impl_k_mutex_lock: 0x2000cbe0 took mutex 0x2000d01c, count: 1, orig prio: 0
[00:00:01.249,664] <dbg> nrf_modem: cfun_callback: CFUN callback 0x8501
> Functional mode has changed to 1
[00:00:01.260,192] <dbg> nrf_modem: cfun_callback: CFUN callback 0x108cd
[00:00:01.267,700] <dbg> nrf_modem: cfun_callback: CFUN callback 0x19abb
[00:00:01.275,207] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.283,599] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.293,426] <dbg> lte_lc: cfun_mode_set: Functional mode set to 1
[00:00:01.300,964] <dbg> os: z_impl_k_mutex_lock: 0x2000ca40 took mutex 0x2000d01c, count: 1, orig prio: 14
[00:00:01.311,889] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000d01c lock_count: 1
[00:00:01.320,220] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000d01c: 0 (prio: -1000)
[00:00:01.330,017] <dbg> date_time: date_time_modem_xtime_subscribe_work_fn: Subscribing to modem AT%XTIME notifications succeeded
[00:00:02.245,147] <dbg> at_monitor: at_monitor_task: AT notif: +CEREG: 2,"7170","0093917B",7
[00:00:02.254,425] <dbg> at_monitor: at_monitor_task: Dispatching to 0xf569
[00:00:02.262,237] <dbg> lte_lc: at_handler_cereg: +CEREG notification: +CEREG: 2,"7170","0093917B",7
[00:00:02.272,308] <dbg> lte_lc: parse_cereg: Network registration status: 2
[00:00:02.280,242] <dbg> lte_lc: parse_cereg: LTE mode: 7
[00:00:02.286,376] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:02.296,966] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=0
[00:00:02.305,847] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:02.314,300] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
Network registration prestatus: 2

[00:00:02.327,087] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:02.334,045] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:02.342,437] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:02.352,233] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:02.362,792] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=4
[00:00:02.371,612] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:02.380,065] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
LTE cell changed: Cell ID: 9671035, Tracking area: 29040
[00:00:02.393,646] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:02.400,634] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:02.408,996] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:02.418,792] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:02.429,351] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=5
[00:00:02.438,171] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:02.446,655] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
[00:00:02.455,108] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:02.462,066] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:02.470,458] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:02.480,285] <dbg> at_monitor: at_monitor_task: AT notif: +CSCON: 1
[00:00:02.487,823] <dbg> at_monitor: at_monitor_task: Dispatching to 0xfc9d
[00:00:02.495,574] <dbg> lte_lc: at_handler_cscon: +CSCON notification
[00:00:02.502,929] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:02.513,488] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=3
[00:00:02.522,308] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:02.530,761] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
RRC mode: Connected
[00:00:02.541,076] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:02.548,065] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:02.556,427] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:04.746,276] <dbg> at_monitor: at_monitor_task: AT notif: +CEREG: 5,"7170","0093917B",7,,,"11100000","11100000"
[00:00:04.757,751] <dbg> at_monitor: at_monitor_task: Dispatching to 0xf569
[00:00:04.765,533] <dbg> lte_lc: at_handler_cereg: +CEREG notification: +CEREG: 5,"7170","0093917B",7,,,"11100000","11100000"
[00:00:04.777,740] <dbg> lte_lc: parse_cereg: Network registration status: 5
[00:00:04.785,705] <dbg> lte_lc: parse_cereg: LTE mode: 7
[00:00:04.791,900] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:04.802,429] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=0
[00:00:04.811,248] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:04.819,732] <dbg> date_time: date_time_lte_ind_handler: Date time update scheduled in 1 second due to LTE registration
[00:00:04.831,878] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
Network registration prestatus: 5
Network registration status: Connected - roaming
[00:00:04.847,808] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:04.854,797] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:04.863,189] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)
[00:00:04.873,016] <dbg> at_monitor: at_monitor_task: AT notif: %XTIME: "0A","6220017192300A","00"
[00:00:04.882,781] <dbg> at_monitor: at_monitor_task: Dispatching to 0x10941
[00:00:04.890,594] <dbg> date_time: date_time_core_current_check: Date time never set
[00:00:04.899,291] <dbg> date_time: date_time_at_xtime_handler: Time obtained from cellular network (XTIME notification)
[00:00:04.911,041] <dbg> date_time: date_time_core_schedule_update: New periodic date time update in: 14400 seconds
[00:00:04.922,332] <dbg> date_time: date_time_core_store_tz: System time updated: 2026-02-10 17:29:03-20
[00:00:04.932,617] <dbg> date_time: date_time_core_notify_event: No date-time event handler registered
[00:00:15.916,503] <dbg> at_monitor: at_monitor_task: AT notif: +CSCON: 0
[00:00:15.924,041] <dbg> at_monitor: at_monitor_task: Dispatching to 0xfc9d
[00:00:15.931,823] <dbg> lte_lc: at_handler_cscon: +CSCON notification
[00:00:15.939,178] <dbg> os: z_impl_k_mutex_lock: 0x2000cd70 took mutex 0x2000c7ec, count: 1, orig prio: -1
[00:00:15.949,737] <dbg> lte_lc: event_handler_list_dispatch: Dispatching event: type=3
[00:00:15.958,557] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0001027D
[00:00:15.967,010] <dbg> lte_lc: event_handler_list_dispatch:  - handler=0x0000850D
RRC mode: Idle

[00:00:15.977,050] <dbg> lte_lc: event_handler_list_dispatch: Done
[00:00:15.984,039] <dbg> os: z_impl_k_mutex_unlock: mutex 0x2000c7ec lock_count: 1
[00:00:15.992,431] <dbg> os: z_impl_k_mutex_unlock: new owner of mutex 0x2000c7ec: 0 (prio: -1000)

Shall I send a modem trace as well?

Thanks

[Øyvind]

From the logs I can see that you get a connection and roam on you local network. See line 111 and 112. So this would indicate that it is not an issue with the SIM. 

I'm testing on SDK v3.2.1 with nRF9160dk. This is the log output I'm getting from the https_client sample:

I would recommend testing one of the other Nordic samples available under nRF Connect SDK - Cellular samples or nRF Connect SDK - Networking samples.

If we do see these work, then there might be an issue with the https_client sample. Could you elaborate what you are trying to achieve?

Kind regards,
Øyvind

[Adamcs]

Øyvind said:

Could you elaborate what you are trying to achieve?

I just wanted to use the connection manger in order to easily know connected/disconnected status, where I'm currently using lte_lc_handler and date_time_handler in order to determine when the device has internet access. The NET_EVENT_L4_CONNECTED indicates that the device is on the network, and an IP address, and is able to connect over MQTT, correct?

---

    lte_lc_register_handler(lte_event_handler);
    lte_lc_connect_async(lte_event_handler);

I've tested with another sample, cellular/nrf_cloud_mqtt_device_message, and it's now functioning as expected. 

*** Booting My Application v1.0.0-96e60fa01efd ***
*** Using nRF Connect SDK v3.2.1-d8887f6f32df ***
*** Using Zephyr OS v4.2.99-ec78104f1569 ***
[00:00:00.369,110] <inf> nrf_cloud_mqtt_device_message: nRF Cloud MQTT Device Message Sample, version: 1.0.0
[00:00:00.369,110] <inf> nrf_cloud_mqtt_device_message: Reset reason: 0x10001
[00:00:00.721,893] <inf> nrf_cloud_credentials: Sec Tag: 16842753; CA: Yes, Client Cert: Yes, Private Key: Yes
[00:00:00.721,984] <inf> nrf_cloud_credentials: CA Size: 1187, AWS: Likely, CoAP: Unlikely
[00:00:00.721,984] <inf> nrf_cloud_mqtt_device_message: nRF Cloud credentials detected!
[00:00:00.722,503] <inf> nrf_cloud_mqtt_device_message: Enabling connectivity...
+CEREG: 2,"7170","0093917B",7
+CSCON: 1
+CGEV: ME PDN ACT 0,0
+CNEC_ESM: 50,0
%MDMEV: SEARCH STATUS 2
+CEREG: 5,"7170","0093917B",7,,,"11100000","11100000"
%XTIME: "0A","6220113185720A","00"
[00:00:05.123,199] <inf> nrf_cloud_mqtt_device_message: Connected to LTE
[00:00:05.123,321] <inf> nrf_cloud_mqtt_device_message: Waiting for modem to acquire network time...
[00:00:08.124,084] <inf> nrf_cloud_mqtt_device_message: Network time obtained
[00:00:08.300,811] <inf> nrf_cloud_info: Device ID: nrf-351358811482246
[00:00:08.307,434] <inf> nrf_cloud_info: IMEI:      351358811482246
[00:00:08.307,861] <inf> nrf_cloud_info: Modem FW:  mfw_nrf9160_1.3.7
[00:00:08.307,891] <inf> nrf_cloud_info: Protocol:          MQTT
[00:00:08.307,952] <inf> nrf_cloud_info: Download protocol: HTTPS
[00:00:08.307,952] <inf> nrf_cloud_info: Sec tag:           16842753
[00:00:08.307,983] <inf> nrf_cloud_info: Host name:         mqtt.nrfcloud.com
[00:00:08.308,013] <inf> nrf_cloud_mqtt_device_message: Connecting to nRF Cloud...

I should mention that the net/https_client doesn't actually compile when I build for nrf9160dk_ns. 

c:/ncs/toolchains/66cdf9b75e/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd.exe: app/libapp.a(main.c.obj): in function `cert_provision':
C:/ncs/projects/_cs/https_client_1/src/main.c:108: undefined reference to `tls_credential_add'

I basically just modified it slightly to comment out some parts regarding TLS/certificate in order to get it compiling, though I don't think it would be anything which would cause issues for the connection manager.

Thanks Øyvind

[Øyvind]

Hello, thanks for elaborating.

Adamcs said:

I just wanted to use the connection manger in order to easily know connected/disconnected status, where I'm currently using lte_lc_handler and date_time_handler in order to determine when the device has internet access.

The LTE Link Control is recommended for our nRF91-series which provides functionality to control the LTE link on an nRF91 Series SiP. 

Adamcs said:

The NET_EVENT_L4_CONNECTED indicates that the device is on the network, and an IP address, and is able to connect over MQTT, correct?

Yes, this is correct. From nrf/samples/cellular/nrf_cloud_mqtt_device_message/src/main.c, and the logs look correct in regards to connection and functionality.

static void l4_event_handler(struct net_mgmt_event_callback *cb, uint64_t event,
			     struct net_if *iface)
{
	if ((event & EVENT_MASK) != event) {
		return;
	}

	if (event == NET_EVENT_L4_CONNECTED) {
		/* Mark network as up. */
		dk_set_led(LTE_LED_NUM, 1);
		LOG_INF("Connected to LTE");
		k_event_post(&connection_events, NETWORK_UP);
	}

	if (event == NET_EVENT_L4_DISCONNECTED) {
		/* Mark network as down. */
		dk_set_led(LTE_LED_NUM, 0);
		LOG_INF("Network connectivity lost!");
	}
}

From the logs we see [00:00:05.123,199] <inf> nrf_cloud_mqtt_device_message: Connected to LTE

Adamcs said:

don't think it would be anything which would cause issues for the connection manager.

That sounds correct. My guess is that due to removal of some parts regarding TLS/certificate the sample is connected but is having issues in the send_http_request() (just a guess from my side).

Kind regards,
Øyvind

[Adamcs]

Thanks for your time Øyvind.