Major bug: upgrade shown as a downgrade

The boots are obviously an upgrade for the DK - same stats, higher ilvl, plus gem. Yet it shows as a downgrade:

https://pastebin.com/mNDsgvW6

Where does it show which boots as a downgrade?

I am going to assume you are using the Team Optimizer based on the data that you provided.

There are no boots in the data that you provided… maybe you posted the wrong string?