My iPhone Silent button is not working

Go into setting and you’ll see “action button.” Just scroll to the action you want to use and back out. Should fix the issue.

Assuming you haven't changed what the Action button does on your iPhone, long-press the Action button (you should feel the haptic feedback emit three pulses). To confirm that your iPhone 16 is silenced, short press the Action Button. A "Silent" icon should appear in the Dynamic Island to signal the change.

Hope this helps.

same for me. silents button not working, nothing. 16 pro Max

no any three pulses feeling, after long-press of the action button. However silent icon appears and signalling the changes

Did you do as recommended above?