Unable to upgrade Yasha Earring of Casting to Asuran Earring of Casting

Upon following through the upgrade text pathing with NPC Seika at Idyllshire, I finally select the exchange button and receive the following refusal response: "Unable to complete transaction. You cannot carry more than one of this untradeable item."

After completing searches and verifying, I have 1 single Yasha earring of casting in my inventory, no asuran earrings of castings, and 1 raw Doman Urushi (1 in inventory, 1 on a retainer); I have attempted the exchange both equipped on blm and unequipped on another job - to no avail.

The only thing I can think of is that patch 3.1 has a cross-link error to some other item in my inventory that is being mistaken for an asuran earring of casting.