ANY body download one ui via xda rollback to Oreo via sammobile firmware install from Odin after wipe factory and wipe ches partion after register for ui and u get from fota update from Samsung
I updated one ui from xdaIt's working fine and you never lost your warranty and it's still official my phone one ui make my beast it's too good all function are worked well and jio and Vodafone artel volte work's 100 out of 100 in night mode battery...