Verizon Employs very strict MAC authentication across it's DHCP requests.
So that's probably why you couldn't unless you cloned the MAC.
Once an item connects with DHCP it's BOUND to the mac address at Verizon's Gateway. So that makes hot swap's of routers impossible without the above steps.
You have to release the IP Address of the device that connected while it's connected.
Once it's released the MAC address Binding is broken, and that allows you to connect any other device.
Cisco's are very popular routers, and used by a lot of my friends on Verizon's network .