LX40 can receive SMS but can't send

Using p/n: 1104579 with AT&T SIM. I receive SMS in ACEManager Last Incoming Phone Number.

Quick Test says “successfully send the command” but no msg is received.

This is the 2nd modem we try with this same problem, and we also have the same problem with T-Mobile SIM. What am I doing wrong?

Dear @eguadalupe ,

Welcome to Sierra community!

In order to troubleshoot the problem, can you please provide answers to the following items:

  1. Which FW version is the device running? If it is not latest FW, please try to install the latest FW then recheck whether the problem is resolved?
    FW download: https://source.sierrawireless.com/resources/airlink/software_downloads/lx/lx-firmware-list/#sthash.Rzr3YZFe.dpbs

Besides, can you please share the screenshot of SMS tab in ACE Manager web? It should be at Services>SMS

Thanks

Firmware is already 4.15.3 and I’ve attached SMS settings screenshot

Thank you

also Advanced settings (at default values)