EG-915Q Issue using PPP with TCP

When using a TCP client (Host MCU) with the pppos connection over USB, the TCP connect packet SYN is sent but the SYN+ACK response is lost. I have provided the wireshark capture of both ends in the following image and worked with my IT group to make sure the traffic is sent to the carrier network (AT&T in the case)

Is there some reason that the traffic would be dropped in the modem or by the carrier?

Here is the device and firmware version