the dreadcoil naga become/phase into darktide as I approach the area for world quest
Same here…
Yup, same thing. Scoured the whole quest area, there are some Darktides out in the water, but not the Seekers for the quest objective.
Edit. found 3 mobs directly south of the FP among the Brackfin mobs (outside the indicated quest area). You have to wait for 2 respawn periods, but the WQ can be completed. Obvously there is still a phasing issue with the rest of the quest area.
If you stand outside the quest area, you can see them. But as soon as you enter the quest area, they disappear.