When using shields in either hand, will only block melee damage and will be ignored if shot with an arrow

What I expected to happen was...:
when blocking with a shield, arrows will deflect off the shield and player will not take damage

What actually happened was...:
when blocking with a shield, arrows will hit the player and take damage as if they had no shield

Steps to Reproduce:
I have tested this using multiple shields against skeletons with bows, on multiple worlds. when standing directly in front of a skeleton and blocking with a shield, player will get hit with the arrow and take damage.