it was supposed to be fixed with the last patch but it just happened to me..i reloaded and tried it again and i got the soul..i dunno what to tell you except reload and try again..
Pre-set dragons respawn, because they are occasionally used by Radiant Quests. However, you cannot farm that dragon for souls. Nonsensical? A bit. Good game design? Probably.
it was supposed to be fixed with the last patch but it just happened to me..i reloaded and tried it again and i got the soul..i dunno what to tell you except reload and try again..
Didn't worked.. What i did was, i left the Dragon there and continued exploring. lol