Normal atziri drop??

Hello,
I am currently farming normal atziri, I am on my 100th run and i also got a friend of mine to do approximately 30 run on his side so i can drop Pledge of Hand judgement staff. If i'm not mistaken the drop rate is 1/50 (or am i wrong?). I think I am slowly losing it and i'm starting think Atziri drops are bugged (at least for me). I was wondering if i was just incredibly unlucky or if it was actually bugged. Thank you for your time.