Volte not working
How to make it work?
Volte does not work. Please be aware.
Guys checkout this [I got this info from celoxocis - in future of p2 thread]
First make sure the P2 is allowed for VoLTE provisioning. Connect to a cell and dial *#*#4636#*#* > Phone Information. Scroll down and see what service the provider provisions on the connected cell.
If VoLTE is greyed out it means:
A: That Kuntao is not In the providers whitelist for VoLTE. Which is the case in most European country's because here they only allow Cell Phones that the Providers sell them self to have VoLTE in their network. (aka They use it for marketing). I know about Italian Vodafone and British O2 that VoLTE is provisioned for the kuntao and works on stock ROM. Haven't heard back from those users for latest unreleased Official build by Highwaystar.
If you are one of such users. Please let us know if it works in your European country.
B: The currently connected cell does not allow for VoLTE. Some providers don't allow for VoLTE on all cells.
C: To make sure it's not the cell itself and the provider does allow for VoLTE. Try stock kuntao first or any other phone that has VoLTE confirmed working with the same sim card and that cell/provider.
Or continue your question regarding volte in here
https://forum.xda-developers.com/lenovo-p2/how-to/future-p2-development-t3612708/page62