My Galaxy S20+ SKT has VoLTE, but not an option to enable it and my one network provider can enable it, but my other provider can't

[SnapdragonFan]

I have Galaxy S20+ Korean (SKT) and it has built-in VoLTE feature, however there is no option to manage it (enabling or disabling). And the huge issue is My one SIM CARD works VoLTE on this phone while my other SIM CARD (UCELL has VoLTE enabled by company, but on the phone it doesn't show VOLTE over Cellular status bar icon (meaning the phone either failing to accept it to work or idk.

Don't recommend me reboots, reset connection settings or things like that, which I already tried and didn't work. The phone is completely fine, it is SM-G986N.

Please help me, release an update to control over VoLTE pleaze. My network provider telling me it is my phone at fault for VOLTE not working. My other simcard MOBIUZ has VoLTE working completely fine. The calls are awful without volte on my UCELL card.

[realaud]

You are in the discussion forum for the U.S. We cannot answer questions related to foreign equipment or providers.  You will have to find the forum for your location.

[CasualMember]

Please contact SK Telecom or South Korea's Samsung support.

[LongHiker]

@SnapdragonFan Unfortunately you have landed in the user to user discussion area for Samsung US products and services. To find the discussion group for your geographical area, visit https://www.samsung.com/us/common/visitlocationsite/