Some reset, some don't count and only 1 person in group gets it. (Kill all 4 towers at once before skele king)
Now I'm trying to get the dye one done. Bought purity dye for over 5k. Used it. Thought maybe I messed up. Bought another. Used it. No check mark. Now I remembered I had used this on my wizard already. Bought another, used it on another piece of gear, just in case it was my helm. Nope didn't work on shoulders, helm or gloves. No check mark. 16k wasted. Same goes for buying all the vendor items and weapons.
Yes, I am buying the right thing.
Yes, I have relogged and checked my achievement status.
Just wasted time and effort and gold into this stuff. It's especially annoying when 1 person in the group gets a harder achievement and the other 2-3 people get stiffed out of it.
Anyways, game is ok so far. Looking forward to patches with more content then clear A1-A4 and repeat 4x with an extra suffix. But not a complainer, I just like getting my check marks.