Hello,
What to do if a button or switch isn't working
- Restart your device. If you can't restart your device, try to force restart it.
- Remove any protective films and cases that might block the button or switch.
- Check for debris or dirt around the button or switch, and clean with a soft cloth.
If you need help with Touch ID, learn what to do.
If the button or switch still isn't working, is damaged, or works intermittently, you might need to set up service for your device. Contact Apple Support, then follow the steps to complete your service request.
From:
About the buttons and switches on your iPhone, iPad, or iPod touch - Apple Support