I got the achievements for quest completion in Stonefalls, Deshaan, and Eastmarch (Shadowfen's is bugged due to "run to next quest hub" quests which disappear if you explore early and find the hubs on your own) . But when the latest patch rose from the fiery depths was introduced into the game, I was playing fine until I checked my achievements and noticed that I no longer had those three, and all of them, including Shadowfen, for which I previously had progress, had been taken away and reset to 0/however many quests you need for the achievement. At first I was frustrated because I thought I would have to do all those quests again but it turned into despair as I went to Stonefalls and nothing was reset, all the quests are already done and I cannot do them again. Only the achievement counters were reset.
I'm not a big achievement and/or title hunter to be honest but it's just ridiculous that I'm forever unable to get the Pact hero title (I think that's the one for all the quests) just because a stupid bug grabbed my achievements.