Jayce cannon stance w is bugging on his hammer stance w

Recently trying out the new jayce after the patch update. One thing I have noticed is the fact that normally when you use your w in Cannon stance and then automatically go into hammer stance, it still performs the 3 attacks with 2.50 attack speed but after the patch, using this method instead creates damages of 1 for 3 attacks. Is this a bug or just a nerf they fixed up on jayce? Thank you.