Knight Gaunt attacks doing nothing

PC.
I'm using Knight Gaunt as a specter, and one of his basic attack swings that he uses when standing in melee never has a hitbox, or perhaps only occasionally does. If it misses once it continues to miss no matter how many times in a row its used until he resets himself with his bird form attack.

Could be other instances of him missing attacks for no reason. Please look him over.