EM7565 reilablity issue on ModalAI-VOXL1

I am working with a VOXL 1 flight deck that runs Yocto Linux. Until now I’ve been using their modem add-on board that houses the RC7611 and everything works just fine. We now have a need for B43, so we’re working with the EM7565 plugged into a M2-to-USB adapter and then plugged into the USB port on the VOXL frame. I have verified that this works just fine on x86 Ubuntu.
The VOXL system starts up, EM7565 connects to my LTE carrier (AT&T) and works fine for random amounts of time. During that time I just have a simple TCP/IP connection up that is sending very small amounts of data. At some point (5min-2hrs) into the test, data transfer just stops. Even when I terminate the test, I can’t do any further network interaction without first resetting the system. I’m running the latest version of VOXL, which I know includes a qmi_wwan.c that has the EM7565’s VID/PID. Any pointers on where to go from here? Are there commands I can run to show state of the modem that may help in debugging this?

if it works on Ubuntu, that means it is not network/ SIM/ module FW problem.

Probably you need to check if there is network interface drop in dmesg.
You might also see what is the response of AT!GSTATUS? when problem happens.