Airtel VoLTE issue in Asus Zenfone Max pro M1

[jay_mech24]

I ported from Vodafone to Airtel, now in my airtel sim volte enable option is not available.
but when I inserted another airtel sim into my mobile then volte working properly.
And my same airtel sim card insert into another phone then also volte working properly.
I reset my phone totally (lost total data), than VoLTE is working fine, but i lost sim and than get a new Airtel sim than again VoLTE is not coming.
I tried with *#*#4636#*#* but there is no VoLTE enabled option.
Build number 2007.084
My phone is Asus max pro m1.

[mahesweta305]

Why LTE mode is not active?

[pankajfhz]

yar mera to starting se he work kar raha h...Ported 1 year ago from voda to airtel
idont know ...asus such why.....?

try, may work
use airtel sim slot 01
enable enhanced 4g lte mode
(If already on then off enable again and restart)
enable dual 4g
network automode
update latest frimware
or
u can visit asus service center