Yes I think a lot of people have this same problem. I had most of the achievements before the patch that changed the number of barrels required. But now after that I have got all the achievements as in the picture, but the bar still shows 9/10.
Can we please get a fix on this or at least an acknowledgement that it is being addressed. This is the toughest boss in the game and now to not have the hard won achievement is a little disappointing to day the least.
