Thanks for raising this concern. Our technology is on the Verizon network, yes, but our service doesn't move with them. Visible only runs on Verizon's 4G LTE and 5G networks. If you're in an area that only supports 3G or any other network under 4G, then you may experience times of little to no service. Here is the link to the coverage map https://www.visible.com/plan/coverage/, so that you can check any specific locations.
Experienced similar issues going through central OK. Verizon map showed coverage, Visible showed some big holes. Guess that is why we pay lower fees. I don't travel a bunch so just a minor inconvenience. Visible is still worth it, but I can see if you travel frequently this might not be the best option for a service provider.