I have the same problem, after doing this two quests (The Book of Runes takes a long time by the way, the drops are random), the two quests givers offer no option to hand them out. No interrogation point above their head and we can't even talk to them anymore.
I also would like to talk about two other quests in the Howling Fjord that are bugged :
- Send Them Packing : you have to /raise your hand at Abandonned Pack Mules, which is supposed to send them back to the Westguard Keep. Some mules don't even react to the gesture, and even when they do, it does not register the objective
- Danger! Explosives! : you have to throw dynamite at ore blocks in the Whisper Gulch. Each ore blown up creates small fragments on the ground that you then have to pick up, 3-4 at a time. But they despawn so fast that you barely have time to pick one up, which is not how this quest is supposed to work
Thanks for your attention, I hope those 4 quests are fixed soon.
If it's not the right place to talk about these issues, please direct me to the correct area [T]/