Icecrown Citadel - The Lich King - Sealed Chest class drop bug or PL character bugged ?

[liwstar]

WoW Freakz link:
https://forum.wow-freakz.com/Icecrown-Citadel-The-Lich-King-Sealed-Chest-t563956.html
https://www.wow-freakz.com/npc_finder.php?npc=36597&&&&name=the-lich-king
https://www.wow-freakz.com/item_finder.php?item=51315&&name=sealed-chest
Bug description: So a while back i did do an report on this issue, sos Yesterday i finnished shadowmourne on my dk and then the Sealed Chest dropped first try, i was surprised as i did shadowmounre fist time on my palla in 7.1.5 date 3/31/18 and this quest item never dropped as first time i thought it was 1% chance i saw on wow head, but then i kinda gave up as i assumed it was bugged until yesterday when it dropped on my dk first try after getting shadowmoune, So my question is, Is it class bugged or was it bugged in 7.1.5 and then my palla became bugged or was my dk very lucky?

When i did this quest on palla it didn't drop as i did assume it was 1% as it said on wowhead back then when i did the quest on palla https://www.wowhead.com/item=51315/sealed-chest i didn't know back then that it was bugged so i returned the quest thinking it was 1% drop and you get it after you Finnish the quest line but that item never dropped on palla when i had the quest https://www.wow-freakz.com/quest_helper.php?quest=24748&&name=the-lich-king-s-last-stand so i when i completed it i returned it and thought it would drop afterwards as it never did not before or afterwards i finished that quest i would have reported it earlier if i knew it was bugged back then.....

Proof: so these screens will show that it dropped yday and that my dk has done and then my palla (no drop and date of my first shadowmourne and that it misses those quests from the sealed chest that should have dropped a long time ago but never did until yday on my dk (gray low lvl undone)(green completed)