I have the top and bottom key pieces, and i can get in to the chest room, but the chest itself will not open and i am not getting the achievement for it in the WvW pane either.
I have not opened it on this character yet let alone in the last 24 hrs.
Whilst this won’t be helpful for you, the Red JP Chest opened fine on Maguuma, however I am on the red side, not sure if SOS or TC have had the same luck.
Same problem as op here, opened all other borderland chests and eternal chest without any problem. did red puzzle on 2 days with different characters now. Chest won’T open, no achievement.
I acquired both pieces of the key in the emerald jp on Tarnished Coast yesterday, but couldn’t get completion for the jp and couldn’t open the chest with the key halves.
update, tried the two key halves in the Ferguson’s Crossing blue borderlands and it worked there. At least I did not have to do that entire jump puzzle.
It looks like the problems root was that there was a fight going on near the chest when I completed the puzzle and that the door was opened already when I entered the chest room. After another day of wait and entering the chestroom “the regular way” I got my achievement.
