I was finally able to pop in and do it early yesterday morning. I had killed the blue-beam-bug-holders several times over the previous days of waiting, so don't know if that was actually related or not. It's true that the boss drops all three orbs of the light upon death.
I reported this to a GM after banging my drum near the altar for 2 hours. The response I got back was something like, "We think it's being caused by a swarm of skeevers but we have our best archmages looking into it".