I am not sure if this is a bug or if I’m missing something. When I do “Best in slot”, I already have a few items on the list. However, it is still putting a line over my item, and suggesting the same item as an upgrade.
It’s not really a big deal, but it’ might be some kind of bug that you would like to look into.
For me it’s 885 (Heroic) version of “Perfectly preserved Cake” trinket, and the “Tearstone of Elune” ring. None of them are modified with any stats or titanforged etc upgrades.