Problem with Master Diver/Sunken Treasure

I seem to have developed a problem with treasure chests and wonder if it is a bug. Yesterday I finished the Master Diver achievement for the second time. The achievement reset back to 0/10. I got an extra key from drop at Karka Queen. All the chests should have reset, but they haven't. I went to several chests, all of which were in the "open" position and no way to interact. I traded key to an alt, same thing. Reset happened a little while ago and I just logged on and again tried to use the key. Every chest I went to is still open. So are keys from drops basically useless? Am I doing something wrong or missing something?

Thanks for any insight.

Check the Bugs subforum, there is a thread there with plenty of people complaining about the same issue.

see also: https://en-forum.guildwars2.com/discussion/41528/sunken-chests-not-resetting

Apparently everyone knows about this, yet there is no word about anything being done. I'm still collecting keys in the vain hope I may someday find a chest that can be opened.

@"Biff.5312" said:Apparently everyone knows about this, yet there is no word about anything being done. I'm still collecting keys in the vain hope I may someday find a chest that can be opened.

There is word, actually. Sorry I didn't manage to scroll to Gaile's actual post, but she is quoted here https://en-forum.guildwars2.com/discussion/comment/545720/#Comment_545720

They are working on it.