Hi Team, 

One of our customer is using SLED 15 SP5 with KDE Plasma X11 and the fprintd package to unlock their desktop using the laptop's(HP ZBook Fury 17.3 inch G8 Mobile Workstation PC) fingerprint reader. The customer reports that this setup worked fine for several weeks. 
However, the most recent "zypper up" update performed this morning seems to have broken this functionality. Now, they can't unlock the desktop with their fingerprint and receive an "Unlocking failed" error message, requiring them to enter their password manually as they did before.

Even after reinstalling the "fprintd" package and re-enrolling the fingerprint, the customer still receives the "Unlocking failed" error message when attempting to unlock the desktop with their fingerprint.
The output of
journalctl  -u  fprintd
gives:

#  journalctl  -u  fprintd
Jan 15 09:34:51 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 15 09:34:51 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 15 09:35:21 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 15 09:35:43 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 15 09:35:43 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 15 09:35:55 HP-ZBook17-G8 fprintd[16081]: Authorization denied to :1.345 to call method 'Release' for device 'Synaptics Sensors': Device was not claimed before use
Jan 15 09:37:39 HP-ZBook17-G8 fprintd[16081]: Authorization denied to :1.345 to call method 'Release' for device 'Synaptics Sensors': Device was not claimed before use


Starting the fprintd service again now leads to the fact that the service is automatically stopped by SLED some seconds after starting it (and obviously fingerprint recognition still does not work from the desktop lockup screen).

─(rootHP-ZBook17-G8 - Thu Jan 18 12:44 )-[/home/DAV-LOCAL]
└─# systemctl status fprintd.service  
○ fprintd.service - Fingerprint Authentication Daemon
    Loaded: loaded (/etc/systemd/system/fprintd.service; disabled; vendor preset: disabled)
    Active: inactive (dead)
      Docs: man:fprintd(1)

Jan 18 10:32:51 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 10:33:17 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:33:17 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:33:47 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 10:39:53 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:39:54 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:40:23 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 12:43:49 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 12:43:50 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 12:44:19 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.

┌──(rootHP-ZBook17-G8 - Thu Jan 18 12:44 )-[/home/DAV-LOCAL]
└─# journalctl  -u  fprintd
Jan 18 10:30:36 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:30:37 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:31:07 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 10:32:21 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:32:21 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:32:51 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 10:33:17 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:33:17 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:33:47 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 10:39:53 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 10:39:54 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 10:40:23 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.
Jan 18 12:43:49 HP-ZBook17-G8 systemd[1]: Starting Fingerprint Authentication Daemon...
Jan 18 12:43:50 HP-ZBook17-G8 systemd[1]: Started Fingerprint Authentication Daemon.
Jan 18 12:44:19 HP-ZBook17-G8 systemd[1]: fprintd.service: Deactivated successfully.


I saw this in the supportconfig logs. 

# /usr/bin/systemd-delta --no-pager                                                                                                                                          
[EQUIVALENT] /etc/systemd/system/default.target -> /usr/lib/systemd/system/default.target                                                                                    
[OVERRIDDEN] /etc/systemd/system/fprintd.service -> /usr/lib/systemd/system/fprintd.service  
That suggests they may have changed the config of the fprintd service.

Also messages like this:
2024-01-14T10:13:46.692715+01:00 HP-ZBook17-G8 fprintd[930]: libusb: error [udev_hotplug_event] ignoring udev action change


Please suggest on this. 


Thanks
Revanth