Tcpdump on WAN port (usb0) doesn't capture rx packets (EM12G)

tcpdump on my EM12G wan port captures only tx packets. It doesn’t capture any rx packet.
EM12G is an integrated module in my controller box & I am trying to ping from the controller itself.
I dont have QUECTEL_BRIDGE_MODE enabled in gobinet driver.

Is this a known issue?

Dear SanjibDas,
Thanks for your inquiry in Quectel forum.
It is better to provide the firmware version that you used now. Then we can help to check it. And for your issue, it s better to provide the debug log to us, you also can send email to to get the support from local side. Thanks!