This might be related. https://www.verizonwireless.com/support/knowledge-base-218813
Important bit I think some people are worried about is that if the baseband is not certified for Verizon 4G and VoLTE then you won’t even be able to activate the device on their network at all. Thats one of the big reasons I was interested in the Quectel EM06, in the specifications they at least make it clear that certification for Verizon along with other major US carriers was in progress. The check mark for certifications on the broadmobi site doesn’t seem very specific.