Not sure if I should put this in the Bug forum or not but here goes... While doing the <Magnificence of Leather> daily I have "Learned" some of the same recipes that I already had. Had this happen on my Tailor too with the Imperial Silk. Shouldn't this work like Inscription and not "teach" you patterns already known?
Welcome to Blizzards wonderfully buggy world of RNG, it does not take in to consideration anything you have already won/learned its is completely random. Perhaps the real uestion would be does Blizzard have any intention of fixing the RNG problem they have created?