Today I found something unusual and it made reference to the Kinscourge. That got me interested in some of the lore, which I started reading on the wiki. Very cool stuff. It talked about the past, when he was an arena champion and the dragon he fought. He was awarded the star of the champion for that battle, which he pinned to the dragon and burried it. The dragon later returned as undead and when you kill it, you get the star.
So I went to my chest of unique items to look at the star I knew I had from a previous kill. It was not there. I searched all my storage and nothing. Nothing in inventory either. Welp, no biggie. I’ll just go kill it again. I did so. Looted the Star. Guess what? It created 2 stars in inventory!
So, my thinking is that somehow it became an invisible item in inventory, which makes me think about the bug that has been reported about people loosing items from chest and inventory - might they still be there but in some sort of digital black hole?