Samsungand both have an ultrasonic fingerprint sensor that is hidden under the display. The new technology means you won't find a sensor on the back or side of the phone, as is the case with the Galaxy S10E Galaxy S10E capacitive fingerprint reader.
But because the technology is new and this is the first time we have seen it on a smartphone. There will certainly be some hiccups.
If you are in the S10's ultrasonic fingerprint sensor, there are five things to try.
When you add a fingerprint to your device, hold the phone as you usually do and place your finger on the screen at the same angle and from the same place you will most likely do each day.
In other words Do not place the phone flat on a table and lift your finger straight up and down the sensor. If not, that's exactly how you usually unlock your phone.
Some have been more successful in placing their finger over the sensor and leaving it in place until the phone says you lift your finger from the sensor.
This prolongs the amount of time it takes to record a fingerprint, but additional time the sensor must read and map your fingerprint can only make a difference.
Do not delete
The installation interface instructs you to move your finger around between each scan. This is correct, but do not move drastically around you. Instead, just shift your finger between the fingers between scanners.
If you just can't get the reader to work with a certain fingerprint, open Settings > Biometrics and Security> Fingerprint and remove the specific fingerprint and re-register it.
Update phone software
On the launch day, Samsung released an update for the Galaxy S10 series, and one of the enhancements includes better performance for the fingerprint sensor.
To improve the fingerprint sensor performance, make sure your phone is running the latest software. Open Settings and select Software Update > Download and install and follow the instructions if an update was found.