I found a bug with the hero editor a few months ago, and since it hasn't been fixed yet, I thought I'd report it.
For a couple of my heroes, I'm getting the yellow exclamation mark in the hero editor that pops up when you got a new gear item. When I go into the slot where it says the new item is, none of the gear is flagged as new. If I go back to the hero overview, it still shows the exclamation mark, and I can't get it to go away for that slot.
I don't remember 100% how this started appearing. I think it might have had something to do with quickly hovering over multiple items, then recycling an item that I had just got in my last match, and was still flagged as new. Maybe the new flag never was cleared before the gear was dismantled.
I'll try to post screenshots soon.