Wireless Joint

Hi, I'm new to LTE and got a Sierra Wireless LX-40 modem for a backup/failover and was trying to get it to connect to LTE using AT&T. I get a good signal at home and LTE/4G on my smartphone but the modem stays at 3G all the time. I have 2 antennas hooked up and the directional/yagi at home is at 90 degrees from each other pointing to a tower nearby. I took it mobile and found a close local tower and it still won't connect to LTE, it stays at 3G. There's a very strong signal at the tower. Even going into a large town it stays on 3G and won't connect to LTE. The modem support people at first said it was the antennas, so I took it to the tower with 2 paddle antennas. Now they say it's the sim card, I called AT&T and he said it should work. Is there setting on the SIM that won't allow a 4G/LTE connection and only 3G?

Thanks for any suggestions.

Look for the ALEOS software configuration manual, the manual is free. Best I could find. No experience with it.

Any reason you went with that industrial iot router?

When I can Ill lookup commands, but you may want to try and use the commands for setting up the Sierra mc7455. Search the modem tutorial forum for it