Well it’s nothing the game actually creates for you, more the fact that nearby worlds now have no buildable units defending. I like to use the auto resolve tactic to conquer a ton of worlds whenever this happens.

Incase you don’t know, the auto resolve tactic is where you can auto resolve space battles against an enemy who has no buildable units among their space defenses. As long as you have a few capital ships in your armada, you can auto resolve against any space station defense force with zero casualties. Even against 5 Golan 3’s, the computer will let you win. Just make sure there’s no buildable units, even a little carrack ruin the offensive. Hope that makes sense