Resolved after 23rd Dec update : VoLTE gone after one ui 4 update..

[eklavya19]

I am having S21 ultra US version.. Using it in India.. I updated it to one ui 4.. Now data goes off while in call on my airtel Sim and JIO esim which is pure VoLTE, is not working..

Checked the diagnostics and found that VoLTE provisioned flag is off and I am unable turn it on..

Please help. 

Regards, 

Pradeep Pol 

[BVikram]

All because of the latest firmware that you updated is not compatible for US region Handset. Sad thing is server should not push the firmware to your mobile as this is none Indian region version. Why to push and block mobile services.Just like you few other users also reported same.

[mahi1509]

How you got US version in India?

[eklavya19]

My friend who stays in US gifted me..

[Charan88]

I need such friends too who gift me a 1000$ phone 😆

[mahi1509]

US carriers don't use volte right?
I am asking

[Iditri]

They use LTE. What you're talking about is EDGE and 3G. It will be discontinued from next year.

[eklavya19]

They support both LTE & VoLTE.. US version Sims are working fine and getting VoLTE option for US SIM in same phone but when we put Indian Sim like JIO which is pure VoLTE and airtel which works with both LTE & VoLTE but don't get VoLTE support..

[Fej]

I am facing same. Did you fined any fix for this?

[eklavya19]

Not yet.. Waiting for official update to fix this..