I'm assuming this due to the floor mechanic on Elegon, but when we were reaching the final phase on Heroic Elegon I would drop my doomguard in the middle where we were stacked. However, instead of casting doombolts like normal he proceeded to just hang out while we wiped to the enrage at 3%. Luckily, we ended up killing it at the end of the night, but this is a pretty huge bug considering the tightness of this enrage.

I'm posting a link to our World of Logs for the night, so you can see that I used a doom guard 3 separate times under the buffs gained/ buffs cast section under my name. You can also see that my doomguard did zero damage throughout the night.

http://www.worldoflogs.com/reports/rt-lyg49997qjfklb04/details/8/?enc=bosses&boss=60410