@m11k Sorry, I completely missed your post. 
My board runs Linux fine without changing any BIOS settings (I loaded BIOS default settings before I started to play around with Windows and some Linux NAS distros). Currently, I'm running Unraid 6.12.6 which uses kernel 6.1.64. But for testing I also had Ubuntu 23.10.1 Desktop running fine before, which comes with kernel 6.5.@chripo, I would be interested to compare BIOS settings with you, and am curious which Linux distro you are using. I just got this board (CWWK-ADLK-NAS-V10) w/ the N305 CPU, and I've been struggling to get it booting for several days. [...] All of the recent installers that I tried (Debian 12, Ubuntu 23.10, Proxmox 8.1, Fedora 39) cause the system to hard-reboot about a second after grub starts booting the kernel.
You are right, BIOS defaults should be safe. Have you compared your BIOS version an date to mine (v5.27, CW-ADLN-NAS-10, 11/15/2023 14:20:54)? And do we really talk about the same board (I have CW-ADLN-NAS-10, you mentioned CWWK-ADLK-NAS-V10)?Overall, this seems like a BIOS bug to me, or maybe I've got a bad board. The BIOS defaults should be "safe".
Did you have a chance to test the other RAM stick already?On the off chance it is related to the RAM (which is unlikely, as I ran a full Memtest86+ without issues), I have an alternate stick coming in the mail tomorrow. [...]