They're refering to the Dawnsdrop gear having the equip effect of applying a stack on your character each time you complete a relevant action for 45 seconds. It stacks upto 3 times after 3 crafts and makes crafting faster.Please give more details. Not exactly sure about the buff you mean.
Gilda Star to Gilda dust recipe while giving alchemy proficiency does not proc the Dawnsdrop armour piece to start stacking it's buff