Threads of the originator quest help

OK, why are these astrolabe drops so DAMN RARE?! I've gotten ONE drop in 300+ maps since I started counting. There is NO REASON a quest item drop should be this rare! Is it me or am I doing something wrong? I have nothing on my atlas so they should drop. All 4 voidstones are also socketed.

I also haven't gotten a single drop from one of the new gems either.