Also Green Cornian's seem to be missing the drop item "Cornian's Dagger."

Thanks Kiji! In the next update (not live yet) Mos runs his full script: dragon weapons for every class, with or without a Stimulator, and turning a Busted Dagger into Cornian's Dagger (with a Steel Plate, a Mithril Plate and 25,000 Vesos) while Moira's quest is active. On the drop: Cornian's Dagger never drops, Mos makes it. Green Cornians drop the Busted Dagger while the quest is active (Dark Cornians rarely too) - bring that to Mos.

Marking this fixed. The change ships in the next update. If it still happens after that, please reopen this report.