VoLTE Option is missing on my SAMSUNG Galaxy S21 Ultra

[Antic Team]

Hi

I am using a SAMSUNG Galaxy S21 Ultra (single sim, Korean Version) phone. My sim is 4G and My operator provides VoLTE service to the other (S21 Ultra, Dule sim version phone) Devices. When I am going to enable the VoLTE under mobile network there is no option for enable that.

Please Help me with this issue.

[Antic Team]

Here is my friend's S21 Ultra phone VoLTE in the same area....

[ynneL]

Have you tried to see if VoLTE works because I had 2 SIMs in my phone and only 1 network allows me to toggle VoLTE on and off but VoLTE works on both SIMs

[Antic Team]

But in my phone VoLTE option not showing

[ynneL]

Some networks don't allow you to toggle VoLTE on and off only 1 of my 2 allow me to do so. Does VoLTE work on your phone when you make a call does it stay on LTE or does it drop down to 3G?

[Antic Team]

It doesn't allow me.

[Pugs1957]

Where are you based? Who is your carrier? What is the baseband of your device? Please provide the same information for your friends phone as well.

[Antic Team]

I am from Bangladesh. I am using "Robi Axiata Limited" Airtel sim card.
My friend is also.

[Pugs1957]

Please let me have the baseband for each device. You can find this in settings, about phone, software information.

[Antic Team]