When in campaign getting the fiat flux is pretty common. When I go to use it while using my controller the target arc just moves randomly. i tilted forward barely enough to get it to register and it snapped to the right. I looked on this forum to see if there was any similar threads. I found one that never got answered due to OP not responding.
I'm using a PS4 controller being mapped as an Xbox controller.
Oh and I have no issue aiming the trebuchet strike i'm not sure about the arrow storm one yet as i haven't gotten it yet.