I am using Starnet AI so it could have something to do with that but in my current game (Assimilator) every ship in the enemy fleet survives even with a crushing defeat. Likewise, none of my ships disengage despite having a trickster admiral and the appropriate war doctrine. Also the defense grid supercomputer doesn't add +8 plattforms. It stays at 15/15 for a citadel. Does anyone else experience this?