S 24 ultra's display brightness is reduced after september security update. I compared my display with another demo phone in reliance digital mall, that phone is running on february update. That phone's display is looking much brighter (near about 50 percent brighter) than my phone. Samsung is reducing quality of s24 U display & camera because of the upcoming S25 ultra.
Kindly complaint to Samsung customer support through Samsung Members App as error report also send log files Along with this error report for this issue and wait for next update may be fix it by Samsung team soon. If you like please accept as a solution it's help to others users also,click on 3dots in my reply section and click on accept solution . Thanks.
