I also have the problem of the missing achievement "Student of History Trophy/Achievement" on my account, but I do have the emblem and my book is 100% completed. I tried the fixes, signing out, moving the Artifacts around, buying new ones (Skorri's Int/Disc is nice), nothing yet. It'll get fixed, no need to spam the forums pplz. You know it's done, it's just not showing to other Xbox pplz. Take a picture of your completed book, and if you find anyone that says you are a pleb, remember only 4% of Destiny Players have beaten the WotM Raid.