Inside [Temple of the Sun – Eternal Sleep], I killed [Nex of Enoch] and looted the quest item [Soft Body Part]. Right-clicking it started “Crystals or mushrooms?” which asks me to turn in to [Mister Neelo]. However, when I go to the coordinates shown by the quest/minimap, Mister Neelo is not there, so the quest cannot be completed.
NPC does not appear / is invisible → quest is stuck.
