Green blinking star above main hand weapon, no new items, bug?

I have a green blinking star above the main hand weapon (Diablo 3 on Xbox One).

Typically I would think this meant that I had picked up some new item without inspecting it, but it continues to be there even though I've sold all the items except the equipped one.

I tried unequipping the item, and reequipping it, but the start continues to blink.

Does it signify something else?

Or is it just a bug?