i purchased my unlocked galaxy note 10 plus from samsung last year but today after one ui 2.1 update my phone is not unlock anymore, contacted t mobile and they coulden't unlock it and refer me to samsung, samsung could't unlock the phone and sent me back to t mobile again. the only suggestion from t mobile was factory rest which i don't want to do. anyone has any suggestion please?
Currently this process is the only way to without factory reset.
If you have your Samsung account logged in and Remote Controls enabled, you can remotely unlock your device. This will also remove the lock code you currently have stored on your phone, allowing you to set a new PIN or passcode!
You can find more information here: Click Link - Samsung Find my Mobile
Also, you have the option of using Google Device Manager to do basically the same thing. Learn more about it here: Click Link - google support
Log in and Find Your Device using Google Device Manager Here: Click Link - google find my mobile
All above steps doesn’t work. you will Need to take the phone to a Samsung or Authorized Samsung service location, with proof of Purchase to remove the google lock and unlock the device. you can also mail your device in by calling 1-800-SAMSUNG to receive a free shipping label.
Hope this was helpful!
Are you using it on T-Mobile or another carrier? A truly unlocked phone should not get locked to any carrier.