Turn off NAT (turn on passthrough) on 340U Beam Aircard

I have been trying for 5 years to get some kind of cellular internet connection onto a raspberry pi to use while camping in Northern Michigan. The latest attempts last summer and again this summer is using an AirCard 340U.  I noticed it seems to have switched back into NAT mode as the IP address I am getting back is a private pool address.  I went back into windows and ran the utility that the product page says 'permanently' sets it in passthrough mode, but all I get back is a private IP.

Since I am trying to use it in linux, is there some AT command that puts it in passthrough mode? Or is there some other thing I can try?