Are you using a screen protector? If it's not a very high quality product, ie: Whitestone Dome, then that could certainly be the problem.
Remove any inexpensive plastic screen protector you may have installed & try again.
You could also remove & re-do your Finger Prints & see if that helps.
Finally, you could go to Settings > Apps & Toggle Show System Apps & Search for "Biometrics", select it & Scroll down to Storage & Clear BOTH Cache & Data. Reboot & add your Finger Prints again & see if it's resolved.
Thank you RedDogRabbit.
Hi, Certain screen protectors can interfere and cause sensitivity issue with the fingerprint sensor causing the fingerprint scanner to unable to recognize and detect your fingerprints correctly.
Try removing or replacing the screen protector and check if that clears the problem.
If not please remove and rescan your fingerprints, you can also clear cache and clear data by following the steps given by RedDogRabbit and keep us posted.
You tried removing all your Finger Prints & adding them back again?
You Cleared Cache & Data for Biometrics & Rebooted - Added your Finger Prints again?
If yes to the above, Open the Samsung Members app & Click on "Get Help" & run the Diagnostics for "Finger Print Recognition", and see if there's any errors.
Are you using different fingers to register your prints?
When I register my Prints, I use one finger to register 3 of the Prints & one other for the 4th Print.
When you register your Prints, try to get different angles and areas of the one finger that you register 3 times, same with the 4th.. Seems to work fine for me.
Hi, you can try if the fingerprint sensor is not working is wiping the cache partition from the Recovery menu.
Below are the steps to perform clear cache partition.
1.Turn off the unit.
2.Press and hold the volume up button and press and hold the on/off button. When the Android logo is displayed, release all keys ("Installing system update" is displayed before displaying the Android system recovery menu options).
3.Press the volume down key repeatedly to highlight "wipe cache partition".
4.Press the Power key to select. Press the Volume Down button to highlight "Yes" and press the Power button to select. When the wiping of the cache partition is completed, "Reboot System Now" is highlighted. 5.Press the Power button to reboot the unit.