For a while now we have been using the Digi Xbee3 LTE Cat1 with the Hologram SIM, which they make in two versions and we have been using the AT&T version (which actually works with a lot of providers). This version uses the Telit LE866A1-NA chipset internally, and the Digi p/n is XB3-C-A1-UT-001. This has worked well without much issue for a couple years now.
Digi has a second model # of this modem for use with Verizon (XB3-C-V1-UT-001), which uses the Telit LE866-SV1 chipset internally. I have not been able to get a hologram SIM to work in this version of the Xbee at all, even though the modem is very similar and I set it up the same way. I’m wondering if anyone has experience with this model and if there was anything special to make it work.