Could something still not be seated properly or maybe a cable has come lose,?
voxl2:/$ systemctl status voxl-modem
● voxl-modem.service - Modem Initialization
Loaded: loaded (/etc/systemd/system/voxl-modem.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2023-03-02 12:58:06 UTC; 31s ago
Process: 1263 ExecStartPre=/bin/sleep 2 (code=exited, status=0/SUCCESS)
Main PID: 1861 (voxl-modem-star)
Tasks: 7 (limit: 4915)
CGroup: /system.slice/voxl-modem.service
├─1861 /bin/bash /usr/bin/voxl-modem-start
├─2144 /usr/lib/libmbim/mbim-proxy

       ******************└─2208 qmicli --device=/dev/cdc-wdm0 --device-open-proxy --wds-start-network=ip-type=4,apn=cmx500.rohde-schwa

Mar 02 12:58:14 m0054 voxl-modem-start[1861]: Waiting for wwan0 to come up...**
Mar 02 12:58:15 m0054 voxl-modem-start[1861]: Waiting for wwan0 to come up...
Mar 02 12:58:16 m0054 voxl-modem-start[1861]: Waiting for wwan0 to come up...
Mar 02 12:58:17 m0054 voxl-modem-start[1861]: Waiting for wwan0 to come up...
Mar 02 12:58:18 m0054 voxl-modem-start[1861]: Waiting for wwan0 to come up...
Mar 02 12:58:19 m0054 voxl-modem-start[1861]: wwan0 is up!
Mar 02 12:58:19 m0054 voxl-modem-start[1861]: Sierra detected!
Mar 02 12:58:20 m0054 voxl-modem-start[1861]: Starting qmi network...
Mar 02 12:58:35 m0054 voxl-modem-start[1861]: error: couldn't open the QmiDevice: Transaction timed out
Mar 02 12:58:35 m0054 voxl-modem-start[1861]: Error detected! Retrying...****************

Then sometimes it will give 'error: couldn't create client for the 'wds' service: QMI protocol error (5)'

@groupo THanks for your help! One strange thing is that I still don't have the modem listed in my PCs device manager. Still waiting on my emulator to become available to test if we see the 5G broadcast.

Seems like some part of the modem is still not reachable, as I it still cant communicate QMI device which is part of modem @tom have you seen this issue before?

@groupo Wow, trying to save time since I need to remove the SIM after I validate this connecting. Thanks, I was thinking since we were talking to it all was good. Getting some errors when doing status voxl-modem but believe thats because we have a test SIM and it cant connect to a live network.
Mar 02 12:59:53 m0054 voxl-modem-start[1854]: Service: 'wds'

   Mar 02 12:59:53 m0054 voxl-modem-start[1854]:             CID: '102'
   
   Mar 02 12:59:53 m0054 voxl-modem-start[1854]: Error detected! Retrying...
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]: error: couldn't start network: QMI protocol error (14): 'CallFailed'
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]: call end reason (3): generic-no-service
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]: verbose call end reason (3,2001): [cm] no-service
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]: [/dev/cdc-wdm0] Client ID not released:
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]:         Service: 'wds'
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]:             CID: '103'
   
   Mar 02 12:59:54 m0054 voxl-modem-start[1854]: Error detected! Retrying...

Going to see if we setup our BS emulator

So one thing I forgot to mention is we installed the sierra wireless drivers SDX65 on their website but we still arent seeing a modem in device manager as noted in the EM9291 user guide (when connecting USB C there should be QC in ports and Sierra wireless in modems):

@groupo Thanks for the information.
When I follow your other post starting with lsusb I do not see a sierra wireless interface? Do I need to access through one of the debugging ports on the side, instead of the main USB-type C?
Here is what lsusb returned:
voxl2:/$ lsusb
Bus 002 Device 002: ID 0424:5744 Standard Microsystems Corp.
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 004: ID 0424:2740 Standard Microsystems Corp.
Bus 001 Device 003: ID 0bda:0811 Realtek Semiconductor Corp.
Bus 001 Device 002: ID 0424:2744 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

@tom Sorry I had a typo we are using the EM9291 5G modem
but it looks like choosing em9191 did what the documentation showed, got confused when it stated us v2 for sierra wireless board. Thanks!
The does show as active now. but does state ''still waiting on WWAN0 to start up''
We still arent seeing an RF or messages back in response to a DL signal from the Base station ( which sends MIB1 and SIB1), any insight to why that might be happening?
We are trying to connect on n14 which is shown as a supported NR band. Is modem locked to any specific carrier or does 'custom' option change anything that's supported?

How do we activate voxl_modem? We see enabled but not running. used systemctl enable voxl-modem
When going through setup process voxl-configure-modem, we pick 1(V2) 2 (no modallink) and 7 (for custom), we then enter our APN. We get a response of waiting for ttyUSB2 then it gets hung up.

We have been trying to search if there is an issue with USB2, here were some steps we tried on powershell

Any idea for getting this modem activated? The drone is using the Sierra wireless 5G EM9091 modem.