I have noticed in a few games since 3.5 that the AI fleets will nearly always focus on destroying drones surrounding a planet, ignoring other nearby targets of interests (fleets it can defeat easily, shipyard, etc). The AI fleet always try to destroy drones, it will wait there forever until it is destroyed. It is the same strategy the AI uses to invade a planet, send a fleet, destroy ships&drones, invade the planet with a transport fleet. Except in this case, there is never any transport coming.
Has anyone else ever noticed that too?
I have created a ticket #AJZ-662-10426 for this behavior with a save game.