Problem with Auto-Completion Quests

[VeRawr]

I've been experiencing this problem for awhile and I'm not sure where the error lies because I have updated Carbonite (just today, in fact,) but I'm currently on an auto-completion quest and the ? that I am supposed to "click to complete" is nowhere to be found and the quest window never popped up on my screen. While my addons were still in the process of loading, the standard Blizzard UI showed the option to turn in the quest for a brief second, but then Carbonite loaded fully and the option, along with the question mark, disappeared.

The quest I am currently having this problem on (but not the only one I've experienced this with) is
"Once More, With Eeling," ID 27729, level 80, Kelp'thar Forest in Vashj'ir.