I honestly can't tell if this is related, but having some issues on my nix systems after getting the 3.0 ncpa combined upgrade on them.
I noticed my NCPA service in a stopped stated after getting a few "connection refused" on the checks via e-mail. I checked the journel and getting the following kick out from the ncpa_listener.log file.
2023-12-04 12:14:00,915 parent WARNING Daemon - check_pid() - Another instance is already running (pid 1100)
2023-12-04 12:14:22,140 root INFO main - Python version: 3.11.6 (main, Oct 22 2023, 20:33:16) [GCC 10.2.1 20210130 (Red Hat 10.2.1-11)]
2023-12-04 12:14:22,141 root INFO main - SSL version: OpenSSL 3.0.8 7 Feb 2023
2023-12-04 12:14:22,141 root INFO main - ZLIB version: 1.3
2023-12-04 12:14:22,141 parent INFO Daemon - start() - Initialize and run the daemon
2023-12-04 12:14:22,141 parent WARNING Daemon - check_pid() - Another instance is already running (pid 1100)
root 1100 0.0 0.0 19928 2180 ? S 00:03 0:00 nessusd -q
PID 1100 in this particular instance ended up being nessusd and if I stopped the nessus service, started ncpa, then started nessus back up, it corrected itself. I suspect this is short lived, but it could also be random on service restart during patching.