Items with custom attributes do not display armor stats correctly

Steps to reproduce:

1) Obtain 2 custom items with custom armor attributes with commands.

/give @p minecraft:iron_helmet[attribute_modifiers=[{id:"generic.armor",type:"generic.armor",amount:10,operation:"add_value",slot:"head"}]] 1

/give @p minecraft:iron_chestplate[attribute_modifiers=[{id:"generic.armor",type:"generic.armor",amount:10,operation:"add_value",slot:"chest"}]] 1

2) Equip custom armor.

3) Armor stats do not display properly. (area above hearts, see image.)