Expert level taiga armorers missing trades

Update: it's working properly, I just had a 20 villagers long streak of bad luck

In the new villager trading experiments, expert level taiga cartographers are supposed to exchange all types of diamond armor, but after verifying in over 30 villagers, they only exchange boots for leggings and leggings for chestplates, missing the trades of helmets for boots and chestplates for helmets.