I have submited a ticket with this over 4 months ago and got no answer. There was a bug that made the items placed in museum disappear and not award progression. It seems that the bug was fixed, and now the achievement actually works.

But... I finished the quests while affected by the bug (I didn't even know about the bug when I made the quests actually). And now I can't finish the achievement (because the shield and helm are already placed, quests finished, but achievement doesn't count them).



As you can see in the screenshot above the items are placed, but blurred on achievement screen. Is there any way to rest this? I don't mind making the quests again and I want to finish this achievement. I submited a new ticket but since I got no answer to the first one I'm not holding my breath. But maybe someone will answer the forum... fingers crossed.