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.

[Pugs1957]

Hi, I was hoping to see your friend's info as well, to work out the difference between the phones as it's possible your friend may have the international version. Anyway, your device is fully compatible with all bands. I have read some devices don't allow you to turn Volte on or off and will do this automatically. This is different for Indian firmware where you still have the button.

[Antic Team]

So what should I do now?

[Pugs1957]

Nothing , your phone supports 4GLTE so is compatible with Volte. The main difference is you can't make a call and use mobile data at the same time. Also, your phone doesn't support 2G or 3G.
See https://www.google.co.uk/amp/s/www.jagranjosh.com/general-knowledge/amp/difference-between-lte-and-v...