Level System no errors but I don't gain levels only xp?

Here is the code

function onXPChanged(player, XP, Level)
	if XP.Value>=Level.Value * 80 + XP.Value then
		Level.Value = Level.Value + 1
	end
end

function onXPChanged2(player, XP2, Level2)
	if XP2.Value>=Level2.Value * 80 + XP2.Value then
		Level2.Value = Level2.Value + 1
	end
end

function onLevelUp(player, XP, Level)
	if player.Character~=nil then
		for i = 1,5 do
			local fireworks = Instance.new("Part")
			fireworks.Shape = 0
			fireworks.formFactor = "Symmetric"
			fireworks.Size = Vector3.new(1,1,1)
			fireworks.BrickColor = BrickColor.Random()
			fireworks.CFrame = player.Character.Head.CFrame + Vector3.new(0,2,0)
			fireworks.Parent = game.Workspace
			game:GetService("Debris"):AddItem(fireworks, 2)
			fireworks.Velocity = Vector3.new(math.random(-30,30),math.random(-30,30),math.random(-30,30))
		end
	end
end
function onLevelUp2(player, XP2, Level2)
	if player.Character~=nil then
		for i = 1,5 do
			local fireworks = Instance.new("Part")
			fireworks.Shape = 0
			fireworks.formFactor = "Symmetric"
			fireworks.Size = Vector3.new(1,1,1)
			fireworks.BrickColor = BrickColor.Random()
			fireworks.CFrame = player.Character.Head.CFrame + Vector3.new(0,2,0)
			fireworks.Parent = game.Workspace
			game:GetService("Debris"):AddItem(fireworks, 2)
			fireworks.Velocity = Vector3.new(math.random(-30,30),math.random(-30,30),math.random(-30,30))
		end
	end
end

function onPlayerRespawned(player)

	wait(5)
--[[
	local stuff = player.Backpack:GetChildren()
	wait(5)
	for i = 1,#stuff do
		local name = stuff[i].Name
		if game.Starterpack:findFirstChild(name)==nil then
			stuff[i]:Clone().Parent = player.Backpack
		end
	end
--]]
end

function onPlayerEntered(newPlayer)
	local stats = Instance.new("IntValue")
	stats.Name = "leaderstats"

	local Level = Instance.new("IntValue")
	Level.Name = "Crafting_Level"
	Level.Value = 1
	
	local XP = Instance.new("IntValue")
	XP.Name = "CFExperience"
	XP.Value = 0 
		
	local Level2 = Instance.new("IntValue")
	Level2.Name = "Mining_Level"
	Level2.Value = 1 

	local XP2 = Instance.new("IntValue")
	XP2.Name = "MIExperience"
	XP2.Value = 0 


	XP.Parent = stats
	XP2.Parent = stats
	Level.Parent = stats
	Level2.Parent = stats

	stats.Parent = newPlayer

	XP.Changed:connect(function() onXPChanged(newPlayer, XP, Level) end)
	Level.Changed:connect(function() onLevelUp(newPlayer, XP, Level) end)
	
	XP2.Changed:connect(function() onXPChanged2(newPlayer, XP2, Level2) end)
	Level2.Changed:connect(function() onLevelUp2(newPlayer, XP2, Level2) end)

	newPlayer.Changed:connect(function (property)
		if (property == "Character") then
			onPlayerRespawned(newPlayer)
		end
	end)
end

game.Players.ChildAdded:connect(onPlayerEntered)