Why doesn't my DataStore save data?

It is as it says, I need to know why my datastore is not saving data. I've tried many times to fix this but I am not very good with datastore so I need some help with this.

Note: It creates data for the player but then it does not save.

local Players = game:GetService("Players")
local DataStoreService = game:GetService("DataStoreService")
local RunService = game:GetService("RunService")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local DataStore = DataStoreService:GetDataStore("Store")

--// Settings \\--
local StarterData = {
    Coins = 0;
    Knowledge = 0;
    Multiplier = 1;
    Capacity = 10;
    BooksUnlocked = 1;
    BookEquipped = 0;
    BooksBought = 0;
}
local playersavetable = {}
local AUTO_SAVE_INTERVAL = 180;

--// Functions \\--
local function loadStarterData(Player)
    local Stats = Instance.new("Folder")
    Stats.Name = "leaderstats"
    Stats.Parent = Player
    local NotShowing = Instance.new("Folder")
    NotShowing.Name = "NotShowing"
    NotShowing.Parent = Stats
    for statname, statvalue in pairs(StarterData) do

        if statname == "Capacity" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = NotShowing

        elseif statname == "Multiplier" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = NotShowing

        elseif statname == "BooksUnlocked" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = NotShowing    

        elseif statname == "BookEquipped" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = NotShowing    

        elseif statname == "BooksBought" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = NotShowing    

        elseif type(statvalue) == "number" then
            local intvalue = Instance.new("IntValue")
            intvalue.Name = statname
            intvalue.Value = statvalue
            intvalue.Parent = Stats

        elseif type(statvalue) == "boolean" then
            local boolvalue = Instance.new("BoolValue")
            boolvalue.Name = statname
            boolvalue.Value = statvalue
            boolvalue.Parent = NotShowing

        elseif type(statvalue) == "string" then
            local stringvalue = Instance.new("StringValue")
            stringvalue.Name = statname
            stringvalue.Value = statvalue
            stringvalue.Parent = NotShowing
        end
    end
end

local function loadData(Player)
    local Data
    local s, e = pcall(function()
        Data = DataStore:GetAsync("UserId:"..Player.UserId)
    end)

    if s then
        print("Getting "..Player.Name.."'s data was successful.")
    else
        warn("Something went wrong when loading "..Player.Name.."'s data.")
    end

    if Data then
        for statname, statvalue in pairs(Data) do
            Player.leaderstats[statname].Value = statvalue
        end
        print(Player.Name.."'s data has been loaded.")
    else
        print(Player.Name.." has no data! Generating new data.")
    end
end

local function saveData(Player)
    if RunService:IsStudio() then return end
    local Data = {}
    for _, stat in pairs(Player.leaderstats:GetChildren()) do
        Data[stat.Name] = stat.Value
    end
    local s, e = pcall(function()
        DataStore:SetAsync("UserId"..Player.UserId, Data)
    end)
    if s then
        print(Player.Name.."'s data has been successfully saved.")
    else
        warn("Something went wrong while saving "..Player.Name.."'s data.")
    end
end

--
--
--

Players.PlayerAdded:Connect(function(Player)
    playersavetable[Player] = tick()
    loadStarterData(Player)
    loadData(Player)
end)

Players.PlayerRemoving:Connect(function(Player)
    saveData(Player)
end)

while true do
    wait(1)
    for _, Player in pairs(Players:GetPlayers()) do
        if tick() - playersavetable[Player] >= AUTO_SAVE_INTERVAL then
            saveData(Player)
            playersavetable[Player] = tick()
        end
    end
end