Creator tag on custom weapon not tagging NPC?

I have been trying to make a tag that the server can read so it knows who killed who. I put my tag and untag functions into the remote event script so that when damage is dealt, the tag is also made. When the NPC dies, however, the console always returns the tag as nil. What am I doing wrong? I am desperate for help, I've tried figuring this out for days lol.

local debris = game:GetService("Debris")

local function tagHumanoid(hum, player)
	local tag = Instance.new("ObjectValue", hum)
	tag.Name = "creator"
	tag.Value = player
	debris:AddItem(tag, .5)
end

local function untagHumanoid(hum)
	for i, v in pairs(hum:GetChildren()) do
		if v:IsA("ObjectValue") and v.Name == "creator" then
			v:Destroy()
		end
	end
end

script.Parent.DealDamage.OnServerEvent:Connect(function(player, Target, Damage)
	untagHumanoid(Target)
	tagHumanoid(Target, player)
	Target.Humanoid:TakeDamage(Damage)
end)

This script is what tags, untags, and deals damage. I am almost certain this is where the tags need to be.

local hum = script.Parent.Humanoid

hum.Died:Connect(function()
	local tag = hum:FindFirstChild("creator")
	if tag then 
		local player = tag.Value
		local Cash = player.leaderstats.Cash
		Cash.Value = Cash.Value + 10
	end
end)

This is the script inside the NPC. It should find my creator tag but it always returns nil if I put a print statement under FindFirstChild.