Overseer Oversight

These series of quests start with [npc=209318] for me, being at chapter 4/7 Guardians of the Dream.

• The Q'onzu Query

Then [npc=210646] starts:

• Q'onzu's Qualification

After that short quest, [npc=210524] gives:

• Q'onzu's Perception

• Q'onzu's Distraction

• The Answers You've Earned

The reward for druids only is [item=210645].
The series don't end with [npc=211821]. Go back to [npc=209318] at the Central Encampment and he will have a new quest:

• Sky Mother's Ire

Then [npc=210587] and [npc=210585] start respectively:

• [Aviana] Aviana's Assessment

• [Q'onzu] Q'onzu's Quandary

While collecting Bloodied Armor Scraps, mobs will drop [item=208775]:

• Ashphodel Research Notes

Seems like Ashphodel Research Notes is a requirement for [npc=210587] and [npc=210585] to start:

• [Aviana] Uproot the Cause

• [Q'onzu] Appalling Pollen

After that, you will find [npc=210587] alone with a last quest:

• Overseer Oversight

Complete all these quests in order to fix the phasing issue that prevents looting [item=210727].

Just as a personal note from my own experience, completing this final quest is what finally stopped the phasing issue I was experiencing on my Druid that was causing me to not be able to see/loot the Pollenfused Bristlebruin Fur Sample. Once I finished that quest I was able to loot it.

You all make it sound like the phasing is a bug, its likely intended that you have to complete the questline before the reward becomes available.