Fortigate 3g Modem Setting

Hi, we are experiencing an issue with 3g modem (D-Link DWM-221) configuration in Fortigate 50e. We have configured a custom modem with the following settings:

Vendor: Dlink Model: DWM-221 Vendor ID: 0x2001 Product ID: 0x7e19

The configuration works and modem connects to internet. The issue occurs as soon as we restart fortigate. It doesn't detect the 3g modem and We must to disable & enable Modem feature to work. Could you advise to us, please?

Thank you and regards