Originally, this mission created the NPC fleet that you need to find, you get to the system then go back, and that was it. This 'bug' is only kind of a bug, but rather a case of the way the mission is built resulting in a message that you don't expect. System (please complete the following information): 'Mission failed' message even when the flagship is still intact. Landing on Tarazed, a non-Remnant planet, after completing the mission. Landing on an uninhabited planet after completing the mission. In addition, I expect the 'Mission failed' message to appear only when the player dies.
I expect the dialog to trigger only when landing on Caelian after the mission is complete. Observe 'Mission Failed' text at the bottom of the screen. There seems to be no way to perform 'Search for the Korath' without failing it.
In addition, the 'Mission failed' message comes on the bottom of the screen in the middle of the mission, even if the player's flagship has not been lost. After completing Remnant: Cognizance 4, Chilia's dialog triggers on any planet, even uninhabited ones or ones outside of Remnant space.