Why does my level up system not save the leaderstats?

Im guessing this is a simple solution but i cant figure it out.

Script:

local level = game:GetService("DataStoreService"):GetDataStore("Levelsonezo")
local xp = game:GetService("DataStoreService"):GetDataStore("XPonezo")
local axp = game:GetService("DataStoreService"):GetDataStore("AXPonezo") --Stands for amount of xp needed to level up.

function savedata(dataname, playerid, value)
 game:GetService("DataStoreService"):GetDataStore(dataname):SetAsync(playerid, value)
end

game.Players.PlayerAdded:connect(function(player)
 local leader = Instance.new("Folder")
 leader.Name = "leaderstats"
 leader.Parent = player
 local levelz = Instance.new("IntValue")
 levelz.Value = level:GetAsync(tostring(player.userId)) or 1
 levelz.Name = "Level"
 levelz.Parent = player:WaitForChild("leaderstats")
 local xpz = Instance.new("NumberValue")
 xpz.Value = xp:GetAsync(tostring(player.userId))
 xpz.Name = "XP"
 xpz.Parent = player
 local xpn = Instance.new("IntValue")
 xpn.Value = axp:GetAsync(tostring(player.userId)) or 1000
 xpn.Name = "XpNeeded"
 xpn.Parent = player

 xpz.Changed:connect(function()
    print("+XP SAVING")
  if player:WaitForChild("XP").Value >= player:WaitForChild("XpNeeded").Value then
   levelz.Value = levelz.Value+1
    xpn.Value = xpn.Value + 500
   xpn.Value = xpn.Value
   savedata("Levels",player.userId,levelz.Value)
   savedata("XP",player.userId,xpz.Value)
   savedata("AXP",player.userId,xpn.Value)
  else
   savedata("Levels",player.userId,levelz.Value)
   savedata("XP",player.userId,xpz.Value)
   savedata("AXP",player.userId,xpn.Value)
  end 
  savedata("Levels",player.userId,levelz.Value)
  savedata("XP",player.userId,xpz.Value)
  savedata("AXP",player.userId,xpn.Value)
 end)
end)

game.Players.PlayerRemoving:connect(function(player)
 savedata("Levels",player.userId,player.leaderstats.Level.Value)
 savedata("XP",player.userId,player.XP.Value)
 savedata("AXP",player.userId,player.XpNeeded.Value)
end)