TrueNas gives you a lot of options and it isn’t too obtuse. I recommend Scale over Core. Avoid it if you only have the one drive as the os won’t share its drive with the rest of the system. Also, while you can use it with only one “storage” drive, it will complain because it uses ZFS and expects you to set up redundency across at least two drives. Might be a hassle for your form factor, but worth a look.

Unless the info is out of date (which is likely) kern.log syslog or messeges.

Have you checked the logs in /var/logs?

Watch a truenas setup for it snd compare the permissions maybe? I got it working on my truenas server but it takes a long time to spin up so it seemed borked but was just slow to start. Not directly comparable, I know, but any port in a storm.