Probably related to the bug with the "Treasure Hunts You" daily.

Getting same behavior with quest "Shocking Developments", North-western most node at East Shroud (26,18) gives "Unable to locate target." on Hyperion, saw multiple other players having the same problem.

Sylph Daily Quest: Shocking Developments
Time: 6:35pm EST
Frequency: Once, but witnessed multiple players with same issue
World name: Hyperion
Character name: Ruethryl Corana
NPC name: Lightning Channeler
Class/Level: 50 BRD
Party or solo: solo
Area and coordinates: East Shroud (26X, 18Y), North-western most object
Steps:
1. Accept Quest from Daily Hub
2. Use item "Sparkling Scalebomb" on Suspicious Coffer
3. Receive error message saying "Unable to Locate Target" regardless of where you throw the bomb.
4. Tried abandoning and re-accepting quest, same thing happens again.