SIM PIN2 to unlock mobile broadband device

My new Laptop is a Lenovo T470s (S/N PC0PXLX1) with a "Sierra Wireless EM7455 Qualcomm Snapdragon X7 LTE-A" WWAN card. 

After working well for 6 weeks, I am now unable to get an internet connection using that adapter.

Windows 10 network diagnostics tells me I need to "Enter a SIM PIN2 to unlock the mobile broadband device". I can find no way to enter anything.

Tech support at both AT&T and Lenovo have never heard of SIM PIN2 and each blames the other for the problem. I have talked to each several times and have been referred to "advanced tech support." 

My internet provider is AT&T.

This community has referred to a "provider specific software" that solved one participant's similar problem.

My provider, AT&T, has given me two PUK numbers. I suspect their PUK2 may be the SIM PIN2, but I still have no way to utilize that information.

HELP!

[Moved from: Windows Insider Program / Windows Insider Preview / Install, upgrade, and activate / PC ]

what worked for me when I got the same message "Enter a SIM PIN2 to unlock the mobile broadband device" on the WIN10 diagnosis on my Lenovo X1,  I had to create the internet APN for my carrier Verizon (vzwinternet) and it worked.  I was just about to reset the network connections to clear all APN settings. But I found directions on how to create one instead. Once I chose it, the SIM connected immediately.

I had the same problem. I downloaded the latest firmware and drivers from sierra wesite and installed firmware first, and then drivers. At the end of driver installation, do not restart. A network configure program runs after driver installation. After doing this I could use sim and connect to internet immediately.

Network reset fixed the problem for me. 

My problem (with the same troubleshooting message) began after I used a 3G USB dongle. Thereafter an Ethernet network showed which said "No Interner", but was not available to edit as a network adapter. Internet connection on WiFi networks would work, but not through the Cellular network. This problem was fixed by going to: Network&Internet > Network Rest> Rest now> Restart computer.

Look through this thread and you will see instructions for installing the driver.

Have you tried installing the driver the Sierra website?

what will that do I can try it