I’ve seen this multiple times now, sometimes as Noble myself: A Noble snoops someone who definitely has stuff in their journal, yet it comes up blank. It seems extremely common.
When I encountered this bug, I was later turned, and when I snooped again, it worked, filling out the first of my two recorded notebooks (so the blank one never ended up getting recorded, not even as a blank notebook.)
Unfortunately, I can’t figure out an easy way to reproduce this, but I figured it’s worth at least creating a thread so other people can chime in and we can maybe figure out what’s causing it.