Explorer Achievement (maybe not a bug)
There are some maps with areas that count as areas for the [Region] Explorer titles, but don’t have any map completion things in them. I don’t know any specifically by name, but if you look at the wiki pages for each, you could identify any you’re missing.
If you mean you’ve been losing world completion %, that’s because they added a few waypoints over the past few months, make sure you’ve got those.
Genesis Theory [GT] (HoD)
For the Achievement “Been there. Done That” you have to get all the Vista/Poi/SkillPoints/Hearts on the main map (excluding South sun cove, Vertical cliffs and PvP) and on the WvW areas as well that are 4 areas Red/Green/Blue/Ethernal battle grounds.
As far as I can remember/know it, the world explored indicator/progress is linked to this achievement and not to the percentage area explored achievements.
The percentage of area one’s if you got all those (don’t forget the whispers headquarters) you get gifts of exploration and an other achievement don’t recall the exact name of it
hope this helps
(edited by Robin.8136)
The achievement corresponds to areas that you discover when the blurred map parts are filled in, you get a yellow indicator text on your screen when that happens. There are many areas that do not include POIs or the like, which you need for world completion, it`s a different achievement. Often these things are JPs or minidungeons, sometimes they are just empty.
I did it yesterday, so it is most definitely not bugged!
I suggest opening up the shiverpeaks maps in the wiki. They have the explorable areas outlined. Then check against your own opened map which area is missing.
The achievement is accountwide, so it doesn`t matter with which character you do any part.
Map completion and explorer achievements are two seperate things and 100% map completion does not equate into full explorer achievements.
Use this link to find the areas you are missing for each explorer achievement: