Enchanted items (armour and bows do not appear/look blocky)

Enchanted gear for me appears to be a simple large block of the material the gear is made of. But sometimes disappears as the enchanted effect ripples across the helmet (it's the same with all armour). Enchanted bows (I've not seen it happen to any other tools so far) do not appear. They still function like a bow but do not have a texture. As if you are shooting a bow made by Wonder Woman or something.