It's not, you just need to get used to this mechanic.
I did thanks, but Something you might want to consider, When you've exhausted all the picks and you get more from the dwarf, if you exhaust those as well, you have to completely start over. might be an unwanted outcome for players. They could just save and keep trying, but maybe add a failsafe in case, like being able to get more from the dwarf until that particular quest is completed? Great progress on the game btw!