I'm trying to convert stacks of acid bolts into quiver but NPC (Nokkhi Jinjahl) in San d'Oria dont convert them at all...
I tried with 1 stack or multiple with Carnations but still nothing happen. The npc just dont react.

as many stacks of arrows you're turning in to her plus your carnation, you need to have that equal in free inventory space: if you are turning in 7 stacks of arrows and 7 carnations, better have 8 free spaces in your inventory or she won't react when you trade.