Progress bug in A Thorn in Your Side

ectoplasmicninja

In this quest in Coldharbour at the Cliffs of Failure, I sided with Angof to defeat the other champions and then went into the cave to survive the Observer's challenge. The Observer appeared, the Watchers aggroed, and I defeated them, but the quest did not update and the portal did not spawn. Leaving and reentering the cave did not help, but when I logged out entirely and logged back in, I was able to complete it.