@Members_5NkHcgp  Please update the "Topics" of this thread to include the S10 series -  the S10+ etc.  Samsung have not fixed this bug in their April release of UI 4.1 for the S10 and it appears to affect international unlocked phones with model numbers ending in "F".   ... View more

@USBetaModerator  I see your reply is dated November 29 2021 - yet you released UI 4.1 update for the Samsung 10 series at the beginning of April 2022 and that update also disables VoLTE on unlocked international phone models ending in "F".  Specifically the SM-G975F.  So you are taking your time to fix this bug and in the interim have caused a great deal of inconvenience to your users.  Furthermore, you do not appear to have any bug tracking or response online and the only method of reporting bugs is through your app.  If other software developers had this strategy they would be out of business.  The only solution for my self and other users was to flash the phone back to UI 4.0 .  How will we know that a future update will fix this issue? ... View more

I have an unlocked Samsung 10+ SM-GS79F and VoLTE stopped working after the UI 4.1 update.  Endless calls to ATT and Samsung were to no avail.  The update comes from Samsung - not the network provider and local Samsung stores only carry software for phones made in their country  - so if your phone is Australian in origin and you are in the US - they cannot help.  The only method to report bugs to Samsung is through the Samsung app.  They have no online bug tracking that I am aware of.  The only solution is to download Odin and the bios for UI 4.0 specific to your phone and flash the phone back to UI 4.0.  Then you will be able to make and receive calls again.  Make sure you back up everything on your phone first to a computer using  Samsung Smart Switch (you may have to download the app), Samsung Cloud, and Google.  Also, disable your pincode and biometrics on your phone before you proceed with the flash.  This bug was also reported on the ATT community forum and you can read users experience with the discovery of the bug and solution here: https://forums.att.com/conversations/more-att-prepaid-discussions/cannot-make-or-receive-calls-on-non-att-4g-phone-3g-sunset-is-to-blame/6251b822a7e2d409585d269a?commentId=62563942453e2f45c8bcc9c3&page=4 You can download Odin 13.14.4 (the current version) here https://technastic.com/odin-download-samsung-latest-all-versions/https://forums.att.com/conversations/more-att-prepaid-discussions/cannot-make-or-receive-calls-on-non-att-4g-phone-3g-sunset-is-to-blame/6251b822a7e2d409585d269a?commentId=62563942453e2f45c8bcc9c3&page=4 and the firmware for your device here: https://samfrew.com/all/ ... View more