As per your query, we want to inform you that this is not a bug or issue, It happens due to the Adaptive brightness feature enabled on your Samsung device, this feature allows the touchscreen to automatically adjust its brightness based on the surrounding environment, you can follow the below steps for resolve your device issue:
Path: Settings app> Display >then tap the Adaptive brightness switch to activate it/ deactivate it.
If the issue persists, kindly report the problems with a log file. To share a log file, click on the Samsung Members Application (Open Samsung Members Application > Support> Tap on send feedback> Choose Composer> Select error report> select the appropriate issue category> Type your query and send.)
