iPhone 11: Subtle clicking sound and vibrational feedback on performing several actions
Haptic feedback was introduced in iOS10/iPhone7 and you probably have this enabled on your phone. To disable or change the configuration, go to

Settings &gt; Sounds &amp; Haptics &gt; System Haptics


Some users have reported turned this feature off doesn't stop clicking and vibrating. https://discussions.apple.com/thread/250781216. You could try re-enabling and disabling again. Also, try turning off sounds and vibrations to see what happens. 

If it's still not working, you may need to contact Apple Genius or an Apple Authorized Service Provider take a look at your iPhone