Why can't I add a new aspect to this legendary item?

I have a legendary item but when I try to add it to the Imprint Aspect window, it says that is not “Rare or Legendary”. Please, fix. I have a perfect aspect for this but I can’t use it so I’m falling behind in upgrades.

Isn’t the item “unique”? :stuck_out_tongue:

I’ve got this happening to me in game now.

Have a legendary offhand that I want to replace the Aspect on, I can enchant the item, but not change the aspect, it is a Legendary, not a Unique, it is an item that has already been imprinted before.
have tried selling to vendor and buyback, but no change.
Other items work fine just the one offhand I have…