[Q] How to fix fingerprint error. topic

Hi guys, I'm a tech at Sprint of recently and I had a customer come in several days ago with a GS5 with its fingerprint scanner getting an error message prompting the user to restart the device every time we tried to access the it from the settings. Also it doesn't work when trying to unlock through the lock screen forcing us to use the alternative password. The phone is on 4.4.4 right now. Not sure if its nk4 or not.

What we tried:
factory wipe
flashing 4.4.4 nk4

I haven't found much documentation about this issue on the internet. Any help will be appreciated.