EC25-G Verizon - no ipv4 lease out of box


I have an embedded linux project that uses quectel EG25-G, firmware EG25GGBR07A08M2G, and a verizon sim card. Normally I am able to use the quectel-cm script to connect and configure a network interface for ipv4 straight away.

With the latest modem, the script would consistently time out requesting registration and no lease was received. I confirmed various settings with AT commands, nothing seemed out of order except the performance of the modem. Finally after a couple days prodding, I ran quectel-cm again requesting an ip6 lease from vzw. It worked straight away and received an ipv6 lease. Following this, the modem has been working in ip4 mode without issue.

What gives? Is there some registration procedure I might missed? Cosmic coincidence?

Thank you!

This should be accidental, if you can reproduce the problem, you can locate the problem through the usbmon log.