I may have found a way.
Not sure if this can be called a work around.
But someone was saying that if you don’t see the “Zaqali Elders” daily quest listed under “World Quests” in your UI, then it would most likely bug.
If that happens, find a group in GF. Join them and see if the World Quest pops up in your UI.
If it does, do the kill with that group.
And don’t let anyone mistakenly pull as there might be a chance that it will bug out if it despawns and respawns again.
If you’re lucky enough to get the World Quest to pop up in your UI on your shard, you should make a group. I’ve been able to complete the World Boss WQ consecutively this way.
Edit: To me, it seems like certain shards are bugged out regarding this specific world boss WQ, so you just have to find a shard that’s working.
Edit 2: It worked again. I created a group this time, since I saw the WQ popup without bugging out.