Garrison items gone?

[Stan64]

I thought I should try out some Garrison with my friends because I want to finish the mannequin quest. After killing Yagudo Votary in Giddeus for over an hour we gave up.

Seven-Knot Quipu is supposed to be a roughly 7% drop. We got all other items that are around 0,5% drop chance.

I believe that this item isn't possible to get any more. What gives?

For good measure:

Platform: any
ISP: any
Type of Internet Connection: any
Internet Connection Speed: any
Date & Time: 2012
Frequency: always
Character Name: any
Race: any
World: Cerberus
Main Job: any
Support Job: any
Area and Coordinates: Giddeus, whole zone
Party or Solo: Party with 2 members
NPC Name: None
Monster Name: Yagudo Votary
Steps:

1. Kill monster repeatedly, no Seven-Knot Quipu will drop.