EG915 loses connection

Hello, here is my problem with EG915 which loses connection to RPI after a while.

  1. Connecting the device to usb
  2. Starting the modems with a powerkey
  3. Works fine for a (max ~400sec) while (Internet connection and AT commands)
  4. The modem is still detected by the system, but I can’t send anything via USB (AT commands do not respond - I can open serial port, no internet in main device). The net_status led is flashing fast which means data is being transferred.
  5. modem reset with reset_pin or plugging and unplugging the usb helps → back to step 3.

I provide at least 3A power supply, I am using drivers Linux USB Driver with configure to support ECM or RNDIS.
Modem AT settings:

  • AT+CGDCONT=1,“IP”,“plus”
  • AT+QCFG=“usbnet”,3
  • AT+QNETDEVCTL=3,1,1
  • AT+CFUN=1