MC 1.20.4 Attributes being constantly added and removed causes weird behaviour

[Kettle5000]

Just try the default diamond armor set bonus (which is actually not working) or add a set of netherite with 20 extra hearts { "armorSetName": "Netherite Supremacy", "performanceMode": true, "head": { "itemKey": "advancednetherite:netherite_diamond_helmet", "mustBeEmpty": false }, "chest": { "itemKey": "advancednetherite:netherite_diamond_chestplate", "mustBeEmpty": false }, "legs": { "itemKey": "advancednetherite:netherite_diamond_leggings", "mustBeEmpty": false }, "boots": { "itemKey": "advancednetherite:netherite_diamond_boots", "mustBeEmpty": false }, "partialBonusRequiredAmount": 2, "partialSetBonuses": [ { "type": "effect", "name": "minecraft:resistance", "value": 0.0, "interactionType": "self", "interactionDuration": 300, "hideBonusDescription": false, "onlyImmuneToNewEffects": false } ], "fullSetBonuses": [ { "type": "effect", "name": "minecraft:fire_resistance", "value": 0.0, "interactionType": "self", "interactionDuration": 300, "hideBonusDescription": false, "onlyImmuneToNewEffects": false }, { "type": "attribute", "name": "minecraft:generic.max_health", "value": 20.0, "modifierUUID": "d5a7dc88-9405-4398-b1e5-250b4c6dd218", "description": "+10 hearts", "attributeOperation": 0 } ], "hideGeneratedTooltip": false } This causes the players hp to constantly being reset to 20 because it seems that the attribute added by this mod is constantly being removed and added.

[SpaceCat97]

This is because you are using the same "modifierUUID" as the diamond set, each modifierUUID must be unique as specified in the wiki.