In order to enable the setting on your phone, head into the dialer and type in *#*#4636#*#*. When you hit that last *, your phone will jump into the hidden settings menu. Choose “Phone info” and then scroll down until you see an option for “TURN ON VOLTE PROVISIONED FLAG.” Tap that and then reboot your phone (I had to reboot twice for some reason to get it to work). Once booted, head into your phone’s regular settings menu, tap on “More” under “Wireless & networks,” then “Cellular networks.” You should now see an option for “Enhanced 4G LTE Mode” and it should be toggled on.
Sent from my Google N6 on VZ