Have you checked if any issues highlighted in Diagnostics, Samsung Members-Support-Phone Diagnostics -Fingerprint Recognition? sometimes you need to reregister the fingerprints? Remove the fingerprints and reregister, it is generally better to have a few fingers registered twice.
However if issues persist clearing the cache partition can help. Follow these steps:
1. Turn off the device.
2. Connect To Computer or other Device , Press and hold the Volume Up key and then press and hold the Power key
3. When the Android logo displays, release both keys.
4. Wait until the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
