@toalalife Hi there! Sorry for the late reply. I’ve been on holiday and I forgot to check up on this. That is interesting. There are a couple of things I can think of to double check/try off the top of my head.
That particular error happens when iPXE can’t execute the binary, usually because either an architecture mismatch (e.g arm64 on x64) or because secboot fails to verify. Given that disabling secboot fixes it, I’m leaning towards that. (https://ipxe.org/err/2e0080)
So I would say you should double check that your kernel is signed. If you’ve updated them you’ll have to resign the kernel to ensure it keeps working.
The other would be to double check that the shim command is being invoked at some point prior to boot.php being chained. There’s a none zero chance that if you’ve updated FOG, it may have overwritten the modified default.ipxe
Other than that, if you could try and record the boot process I’d be happy to take a look and see if I can spot anything out of the ordinary, I’m also happy to take a look at your kernel or any ipxe scripts etc if you want me to double check if they’re signed or bootable.
As a final note, I don’t think I see iPXE loading the initrd.xz file there, which contains the ram filesystem that FOG uses on boot. I could be misremembering the boot process (I can’t recall if it’s normal for it to not do that if the bzImage fails to verify, or if it loads it prior to bzImage), but if that’s failing to load it might also be worth checking that out, though it shouldn’t have to be signed!