I have tried to collect the Vent sample on southsun twice already. i hit the collect skill, the sample disappears as expected, but the achievement does not updates. Happening to someone else? Im running out of mesmer friends to help me get there
Vent Achievement - Southsun
If you need a mesmer to get to the point, you are probably referring to the sample in the jumping puzzle, which is called Islet.
The vent sample is basically on the ground.
Check a guide if you are trying to collect the right sample (http://dulfy.net/2013/05/14/gw2-southsun-sample-collection-guide/)
I think you are collecting the wrong sample. The vent sample is by the start of the jumping puzzle on the ground covered in steam along the wall. The one you seem to be describing on top at the end of the jumping puzzle is called Islet sample. Hover over the achievement and it will tell you a more specific location.