As per your query, we want to inform you that this feature focuses on the sound, while you are on call with someone. When you are on a call with someone, a Mic icon will come with the calling number, you need to click that number, and your voice focus mode will be on.
Additionally you can find the options by following the below steps.
1) When a call is going on, drop down the quick panel. 2) You will see on the top left corner Mic mode. 3) Click on it to switch to Voice focus.
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).
