Why does my saving script fail to overwrite data?

I have a saving script that saved my data the first time but would not the next times. So I can tell that the problem is overwriting data. I even put in a anew thing to save and it saved it once but would not the next time. Thanks in Advance

Here is my Script I put into "ServerScriptServicee" I have another script that creates everything being saved in this script

local Players = game:GetService("Players")
local DataStoreService = game:GetService("DataStoreService")
local DataStore = DataStoreService:GetDataStore("-xBuckDatax-")

-- This function saves the players data
local function Save(player)
    local key = player.UserId
	local plr = workspace:WaitForChild(player.Name)

    local save = {
        ["SeerBux"] = player.leaderstats["SeerBux"].Value,
		["SpdWaitTime"] = player.WaitTime.WaitTimeSpd.Value,
		["StrWaitTime"] = player.WaitTime.WaitTimeStr.Value,
		["walkSpeed"] = plr:WaitForChild('Humanoid').WalkSpeed,
		["customize"] = player.Customize.Value,
		["Exp"] = player.ExperiencePts.Value,
		["level"] = player.leaderstats.Level.Value,
		["SpdCheck"] = player.SpdCheck.Value,
		['energy'] = player.EnergyCount.Value,
		['enbool'] = player.EnergyBool.Value
    }

    --saves their key and money to the data store
    local success, err = pcall(function()
        DataStore:SetAsync(key, save)
    end)

    if not success then
        warn("Failed to over-write data"..tostring(err))
        return
    end
end

-- This function loads the players data
local function Load(player)
    -- saves the player Id as key
    local key = player.UserId
	local plr = workspace:WaitForChild(player.Name)

    local moneyAlready

    local success, err = pcall(function()
        moneyAlready = DataStore:GetAsync(key)
    end)

    if not success then
        warn("Failed to read data"..tostring(err))
        return
    end

    if moneyAlready then
        player.leaderstats.SeerBux.Value = moneyAlready.SeerBux
		player.WaitTime.WaitTimeSpd.Value = moneyAlready.SpdWaitTime
		player.WaitTime.WaitTimeStr.Value = moneyAlready.StrWaitTime
		plr:WaitForChild('Humanoid').WalkSpeed = moneyAlready.walkSpeed
		player.Customize.Value = moneyAlready.customize
		player.leaderstats.ExperiencePts.Value = moneyAlready.ExperiencePts
		player.leaderstats.Level.Value = moneyAlready.Level
		player.SpdCheck.Value = moneyAlready.SpdCheck
		player.EnergyCount.Value = moneyAlready.energy
		player.EnergyBool.Value = moneyAlready.enbool
		
    else
        Save(player)
    end
end

Players.PlayerAdded:Connect(Load)
Players.PlayerRemoving:Connect(Save)

Here's the leaderboard script in case you wanted it. Not everythin here is saved. I just use this script to create Values, animations, etc. in game.

game.Players.PlayerAdded:Connect(function(player)
	player.CharacterAdded:Connect(function(char)
		local humanoid = char:WaitForChild("Humanoid")
        local animate = char:WaitForChild("Animate")
		local ls = Instance.new("Folder", player)
		ls.Name = "leaderstats"
		local stats = Instance.new("Folder", player)
		stats.Name = 'Stats'
		local Cash  =Instance.new("IntValue", ls)
		Cash.Value = 1000
		Cash.Name = "SeerBux"
		local level = Instance.new("IntValue", ls)
		level.Name = "Level"
		level.Value = 1
		local Custom = Instance.new("BoolValue", player)
		Custom.Name = "Customize"
		Custom.Value = false
		local waittimeFold = Instance.new("Folder", player)
		waittimeFold.Name = 'WaitTime'
		local waittimespd = Instance.new("IntValue", waittimeFold)
		waittimespd.Name = 'WaitTimeSpd'
		waittimespd.Value = 3
		local exp = Instance.new("IntValue", ls)
		exp.Name = "ExperiencePts"
		exp.Value = 0
		local waittimeStr = Instance.new("IntValue", waittimeFold)
		waittimeStr.Name = 'WaitTimeStr'
		waittimeStr.Value = 3
		local power = Instance.new("IntValue", stats)
		power.Name = "Power"
		power.Value = 5
		local energy = Instance.new('IntValue', player)
		energy.Name = 'EnergyCount'
		energy.Value = 22
		local boolenergy = Instance.new('BoolValue', player)
		boolenergy.Value = true
		boolenergy.Name = 'EnergyBool'
		local usebool = Instance.new('BoolValue', player)
		usebool.Name = 'EnergyUsed'
		usebool.Value = false
		local lift = Instance.new('StringValue', workspace.Animations)
		lift.Name = 'Lift'
		local liftanim = Instance.new('Animation', lift)
		liftanim.Name = 'LiftAnim'
		liftanim.AnimationId = 'http://www.roblox.com/asset/?id=2914392738'
	end)
end)