Faced with the same problem. It helped to update the modem firmware. Old version: AT+CGMR +CGMR: LE11B08SIM7600M22 New version: AT+CGMR +CGMR: LE11B14SIM7600M22_221022 Flashing Instructions: To update the module's software, you will need the following files:
Connecting a modem (or debugging) directly via USB:
for all Windows versions: https://drive.google.com/file/d/18d37YLOOnDrlxSXq2aQwQAMinHPGMLBk/view?usp=sharing
for Linux: https://drive.google.com/file/d/1LqArVeNvR3CpOOMfrEGL999W7W-TxGIg/view?usp=sharing
Available for download via the link:
https://drive.google.com/file/d/1t4O6gTTZkQGW6CEIo9JCpMjjQwqoZaTL/view?usp=sharing
Current Software (S2-107EQ / S2-10CYG):
B14_221022 - https://drive.google.com/file/d/10zjUvN5rEJ8viTxraa2jvV1fkjzmAiml/view?usp=sharing
The firmware update process is divided into stages:
Connect the module via USB to the PC
Download and unpack the archives using the links above
Install the drivers
Download and install QPST:
https://drive.google.com/file/d/1K5DxiYI6Ah3ygFKLkLt_xe-94qXrWEeB/view?usp=sharing
Turn on the module (apply power and clamp the PWRKEY to the ground)
Make sure that there are no unidentified devices in the Device Manager.
Move the unpacked firmware folder and the utility folder to the root of any disk.
Open the utility; Status field=grey
7.1. In the utility, click "Load" and select "MDM9x07(SIM7500&SIM7600 Series)"
7.2. In the window that opens, select the path to the firmware folder and after the utility detects all the files that make up the firmware (the lines will turn green), close the window.
7.3. Click "Start"
The firmware process will start (Status=blue field), you can control the process by watching the progress bar in the utility. If the process stops by 1-2% during the update, check the Task Manager for unknown devices during the update (use the driver above)
Upon completion, the green label "Update Success!" will appear (Status field=green).
Press "Stop" in the top menu of the utility and turn off the module CORRECTLY (via PWRKEY or 'AT+CPOWD=1').