Player desync with server after death

[Clexus]

Expected behavior

That shouldn't happen

Observed/Actual behavior

Player client side can do anything, but server side they are just standing there with invulnerability and can't be moved. Kill doesn't work, teleport does work, seems like they are in a state of dead and living.

Steps/models to reproduce

I enabled immediate respawn
below is what I do to players at the time they die in EntityDeathEvent

private void applyLevelEffects(Player player, int lvl) {
        player.getInventory().clear();
        player.getInventory().addItem(getWeapon(lvl));

        addOrReplaceAttribute(player, Attribute.MAX_HEALTH,
                "battle_health_" + lvl, 10);

        addOrReplaceAttribute(player, Attribute.SCALE,
                "battle_scale_" + lvl, 0.25);

        addOrReplaceAttribute(player, Attribute.ARMOR,
                "battle_armor_" + lvl, 5);

        player.setHealth(player.getAttribute(Attribute.MAX_HEALTH).getValue());
    }
private void addOrReplaceAttribute(Player player,
                                       Attribute attribute,
                                       String key,
                                       double amount) {

        var attr = player.getAttribute(attribute);
        if (attr == null) return;

        NamespacedKey nsKey = NamespacedKey.minecraft(key);

        attr.getModifiers().stream()
                .filter(m -> m.getKey().equals(nsKey))
                .forEach(attr::removeModifier);

        attr.addModifier(new AttributeModifier(
                nsKey,
                amount,
                AttributeModifier.Operation.ADD_NUMBER
        ));
    }

I don't know which part triggers the desync, maybe attribute part

Plugin and Datapack List

Luckperms, multiverse, nochatreports, packetevents, PlaceholderAPI, PlugmanX and the test plugin

Paper version

paper 1.21.11-62

Other

For now I delayed the action for 4 ticks and it works fine

[electronicboy]

Setting a players health inside of the death event has never been a supported way to revive a player, this is likely breaking due to the loaded state changes made in 1.21.11

[Clexus]

Setting a players health inside of the death event has never been a supported way to revive a player, this is likely breaking due to the loaded state changes made in 1.21.11

not really wanted to revive player, actually the case was "player have to kill others to level up -> player level up to 5 -> all other players level up to 4 immediately to defeat the level 5 -> all other players contain the player just get killed -> bug occurs"

[kennytv]

You should add a check for if the player is currently dead then, else don't set the health

[electronicboy]

not really sure what you're saying, by the time the death event fires the entity is in the state transition to being considered fully dead, along with all of the side-effects of that, such as being marked as waiting to be respawned (this is a 1.21.11 addition), setting their health to not be dead is generally unexpected to the server at this point