Bug probably.
When i survey system with some other empire it takes really long to discover that there is empire there. Even if there is a planet, and station, and i survied it completly. Research ship just go on with black mysterious station on map.
It is even more interesting with Marauders empires, since the fleet is hostile so it scares off research ship, so unless i border them they could remain silent, more enigmatic than fallen empire.
When i survey system with some other empire it takes really long to discover that there is empire there. Even if there is a planet, and station, and i survied it completly. Research ship just go on with black mysterious station on map.
It is even more interesting with Marauders empires, since the fleet is hostile so it scares off research ship, so unless i border them they could remain silent, more enigmatic than fallen empire.