In options I have my monster ability control set to start abilities when the button is released instead of when it is pushed, but when playing Elder Kraken the banshee missile launches when I press the assigned button rather than waiting for the release. All the other abilities wait until I release the assigned buttons.
I have tested all the monsters on PC and got some interesting results. The ‘release to fire option’ worked properly with most of the monster abilities with the following exceptions: All of Kraken’s abilities; Behemoth’s Fissure; Elder Kraken Banshee Missile and Chain Lightening. I was especially surprised that Elder Kraken had 2 abilities that worked as expected and 2 that did not. I would confirm this as a bug since it only mostly effects Kraken and its variant with one other instance for Behemoth. I would also add that if this is fixed it will have a positive impact on my gameplay, as the abilities that work with ‘release to fire’ have a better user experience regarding timing and aiming.