I have had this happen a few times before, but I didn’t know the issue until the other day. I had some ranged units try to attack an enemy ship that was out of their reach. Before this, the game ran smoothly, but as soon as they tried to attack the ships while it was out of reach, my frames dropped significantly to 10-20 FPS. I then stopped the units from trying to attack the ship, and my frames improved again.
Try it yourself if this also happens to you. Place a ship out in water, far enough where you have ranged units that can’t reach it, and have them try to attack it. Does this issue happen to you too?
Edit: Wait, why is this in discussion? I swear I posted it in bug report… Oh well.