I regularly issue an order to fire my lovely Pandora, only for it to either ignore the order, do the animation of charging up the barrel then nothing happening, or moving to the position even when it is well within firing range. Is there something I am missing? does it need LOS to fire now?

This happens when you shoot just on the edge of its range. It happens to all of us and I'm afraid you'll just havesShoot closer to the pandora.