Azcapa Soul Core Socket on Shields

I recently Socketed x2 Azcapa Soul Cores into my Mahuxotl's Machination shield.

I noticed that my on-kill drop rarity is not affected when equiping/unequiping the shield with the drop rarity sockets on it.

Is there a reason for this? Or is this a bug?


*Update: Solved my issue. The item rarity does not update for skills that can't be used while holding a shield. When looking at the drop rarity, I was looking at a skill that can only be used by quarterstaff's, and thus is unaffected by modifiers on shields.