During improvement, the color of the item to be improved (bottom left of the image) does not visibly change. It's still changing properly in the preview of the next upgrade and in the side bar.
I also noticed this. In the past, the item would get unslotted once it is improved. I was not sure if it is a new feature in one of the addons that I use, but if it's in the base game it seems to be a bug, as it does not update the label.
During improvement, the color of the item to be improved (bottom left of the image) does not visibly change. It's still changing properly in the preview of the next upgrade and in the side bar.
We have repro'd this internally and are looking into it. Thank you for passing this along