LT4120 X5 LTE T77W595. Fixing WCDMA/LTE BAND via AT commands

OpenWRT 23.05 I am trying to set the modem to WCDMA mode via AT commands.
Response

AT^SYSCONFIG?

^SYSCONFIG: 17,0,0,2

After entering the recommended

AT^SYSCONFIG=15,0,0,3

or

AT^SYSCONFIG=13,0,0,3

The modem stopped communicating.

AT+QCFG="nwscanmode",3,1

Also did not give any results. If anyone has had any experience, please share.

ATI
Manufacturer: QUALCOMM INCORPORATED
Model: 4087
Revision: T77W595.F0.0.0.6.6.GC.029 1 [Jul 06 2016 23:00:00]

I assume you're not in the US, correct?

That has nothing to do with OpenWrt.
Please refer to AT Command guide for your modem.