If you've recently repaired your iPhone it could be that you've damaged the Touch ID cable. On the iPhone 5s and SE this cable is tricky to maneuver and disconnect without tearing and, if you do, you lose Touch ID Functionality.
A couple thoughts that might help you out:
# Try removing the Tempered Glass Screen Protector and setting up Touch ID from Settings > Touch ID & Passcode. Add your Left and Right Thumb and whatever your dominant hand pointer finger is. Then "train" the device to better recognize those fingerprints by holding those fingers over the sensor on that initial "Touch ID & Passcode" screen. You'll notice under "Fingerprints" that the corresponding finger highlights in grey for a brief second each time. This is helping the iPhone better account for the variations in your fingerprint.
# Make sure your screen is clean. Take a microfiber cloth and some screen cleaning solution (or rubbing alcohol, if you don't have any lying around) and clean the entirety of the screen. Additionally, make sure your fingers are clean.