I've got the same problem: the nests aren't clickable.
I've tried all the fixes in this thread. Changed instances, logged out, quit the game, ported to stronghold. I've reset the quest about ten times and even abandoned it and started over twice. Nothing works. No idea what to do now. Maybe I'll try another character if I feel like slogging through the first quest again.
Edit: It finally worked, but I don't know what I did differently. It just worked this time. Which is no help to anyone having problems. Just keep trying, I guess.