This also works with other weapons such as a 1-handed sword
In the video, my spear, instead of thrusting in the direction I'm pointing, decides to follow my horse's head while rotating.
This only happens when starting an attack over your mount's head. Otherwise, if attacking to the side and rotating your mount, your attack will point where you're aiming.
I've reported this as a bug months ago but it still hasn't been fixed, which leads me to believe it's intended, which is ridiculous.
Please fix.