The page you’re referencing in Shassar is not one of the latest ones added, it’s from the second set of pages added…
It’s possible for the clue to point you to a page / item that you’ve already collected. When that’s the case, there is no page / item, because you’ve already collected it.
From the thread I linked, the page you’d find in that location is called…
Amber Blades Patrol Logbook
If you go and visit the Adventurer’s Chronicle in Cain’s room, you can check which of them you’ve already gotten. This one’s in the Histories section…
If you already have that, that’s why the page doesn’t show up in the area the clue’s pointing you to.