Hi I was using a prophecy which dropped generic runes. it was on death of siege golem, no condition, 22 rune reward, fulfilled 0/4 times. It has been already like 8 hours of game time since I got this rune and no runes of havoc have been dropping. Literally the next monolith I ran after deleting this prophecy dropped a rune of havoc. I was running around 550-650 corruption for the past hours of play time. I hope I gave you enough information to see if it was really a bug or what.