Sack of Fish Bait

I have been trying to complete the Sam quest "Sacred Katana". This quest requires me procure a Handful of Crystal Scale by defeating an NM popped with a "Sack of Fish Bait". According to all the guides that I have read I cam get the bait from Goblin Robbers in Zi'Tah. Supposedly its a common drop. I have gone from lvl42 to lvl 50 fighting these goblins without 1 drop. Am I doing something wrong or are all the guides incorrect? Would appreciate a little help. Thanks in advance.

It's the right item from the right mob in the right zone and the drop rate is indeed very high.

Only thing is you either already have one and forgot, use item search. Or they broke it during a previous update.