So I’m not personally locked into CDMA vs gsm, its just that the carrier appears to be. The exact quote from the device page is
“[US Version] Compatible with GSM Networks including AT&T, T-Mobile and MVNOs (Mobile Virtual Network Operators) who utilize AT&T and T Mobile networks. This device is not compatible with CDMA Networks such as: Verizon, Sprint and US Cellular”
Looking at it more, it sounds like the problem is specifically the 13 band not being supported by the device.