My Pixel 2 has the fingerprint sensor setup to unlock but noticed that when I receive a notification and double tap it, it unlocks the phone without using a fingerprint.
Could be that I've missed a setting somewhere but not sure where?
I've sorted it. Looks like my Pebble watch was setup within the Trusted Devices in Smart Lock. Removed this and still get notifications to my Pebble but also requires my fingerprint to access any content.