Was on Eldersblood Peak, was a Frost Dragon I saw circling in the distance, I had already claimed the word/dragon that was on Elderspeak so I fast traveled their, fought the dragon and no soul or "burning to bones". My guess is it has something to do with having already killed the dragon in the altar

And I say that cause I was talking to a friend while we both were playing and he mentioned a bugged dragon at a Dragon Altar then realized he had been here before