That's annoying... Luckily it worked for me. I did notice some other achievements in the zone took a little while to register, but a day seems too long.
Yes, I have this too. Support not being very helpful either, they just keep telling me to reloadui or drop the quest, which I can't because it's a completed quest...
I've had an open support ticket for a few days now. They also asked me to remove all add ons and drop ui but the issue remains. I will update here if I receive a resolution.
Because there is a thread already open on this topic, we're going to close this one down so that all feedback can be consolidated in one place. You may continue the discussion here.