Keeper Leena missing on last step of "The keeper vault"

logging out and back in fixed it for me

to clarify how I fixed this:

I was having this issue - I teleported to Summit, defeated the bird boss again, talked to the old man in the cage, including the “quest” dialogue option (golden marker). At this point I tp’d to town, nothing there. I defeated the Boss again, thought it was bugged forever. Then I just logged out to character selection and logged back in (from Town - The Keepers Camp in Divine Era). I was teleported automatically to the next part of the game as I logged back in, where you find the piece of Epoch in the Void or whatever. So a simple log out fixed everything, given you’ve beaten the Boss and exhausted the dialogue option with the old man in the cage.

Is this on your high level character that’s had the quest active and stuck on the low level character where you’re still at that point of the campaign and still in the act?

Solution worked for me : just walk to top left out of “keepers camp” to “fortress gardens” and the quest auto triggered to the next step

I’ve completed the whole campaign on my main. This bug was on my alt.

Same here, stuck at that step. I tried to travel out and come back but no success. The kidnapping scene at Northen Road happens on each visit but nothing triggers my quest.

If you’re stuck just skip it and keep going. The quest notification will just stay there.

Honestly, I did not know the impact on my campaign so I restarted a new character.