Carrier for Netgear Aircard 779S

Nov 5, 2018
I picked up an unlocked (boost branded) wifi hotspot for travel in the US. It works fine with my Canadian Carrier (Virgin/Bell) but I can't get it to work with any of about a dozen pay/go US carriers. It just doesn't recognize the SIM. I've entered the apm settings manually based on their sites but nothing.

Any ideas?

Boost doesn't have the greatest rates so they're the only ones I haven't tried.