Armor Attributes doesnt stack

Im trying to make a unique armor for the server, but there is a problem with attributes. Logically, it should stack like +6 +6 +6 +6 = 24 extra health, but instead it just +6 Here is the armor items code ArmorItems:[{id:"minecraft:iron_boots",count:1,components:{"minecraft:item_name":'{"bold":true,"color":"green","text":"Неприятные ботинки"}',"minecraft:enchantments":{levels:{"ethrium:burning_thorns":4,"minecraft:thorns":4,"minecraft:mending":1},show_in_tooltip:true},"minecraft:enchantment_glint_override":false,"minecraft:attribute_modifiers":[{id:"max_health",type:"generic.max_health",amount:6,operation:"add_value",slot:"feet"}],"minecraft:trim":{material:"minecraft:emerald",pattern:"minecraft:silence",show_in_tooltip:false}}}, {id:"minecraft:iron_leggings",count:1,components:{"minecraft:item_name":'{"bold":true,"color":"green","text":"Неприятные поножи"}',"minecraft:enchantments":{levels:{"ethrium:burning_thorns":4,"minecraft:thorns":4,"minecraft:mending":1},show_in_tooltip:true},"minecraft:enchantment_glint_override":false,"minecraft:attribute_modifiers":[{id:"max_health",type:"generic.max_health",amount:6,operation:"add_value",slot:"legs"}],"minecraft:trim":{material:"minecraft:emerald",pattern:"minecraft:silence",show_in_tooltip:false}}}, {id:"minecraft:iron_chestplate",count:1,components:{"minecraft:item_name":'{"bold":true,"color":"green","text":"Неприятный нагрудник"}',"minecraft:enchantments":{levels:{"ethrium:burning_thorns":4,"minecraft:thorns":4,"minecraft:mending":1},show_in_tooltip:true},"minecraft:enchantment_glint_override":false,"minecraft:attribute_modifiers":[{id:"max_health",type:"generic.max_health",amount:6,operation:"add_value",slot:"chest"}],"minecraft:trim":{material:"minecraft:emerald",pattern:"minecraft:silence",show_in_tooltip:false}}}]