The data of the minute stat doesn't save all the time, help?

im making a homestore so, I added a script in ServerScriptService to make 2 stats in my leaderboard. the 1st stat counts how much minutes did the player spend in the game. I got this Global LeaderBoard model from the toolbox :https://www.roblox.com/library/5602215077/Global-Leaderboard?ViewInBrowser=true&CreatorId=139133614&SearchId=5B919599-265C-4766-ABAE-0BDE3D01FC1C&Category=Model&Position=2&SearchKeyword=&CreatorType=User&SortType=Relevance and I added it to my homestore and the 2nd stat counts how much outfits the player bought from my homestore.

script:

--[[
    @author TwinPlayzDev_YT
    @since 1/28/2021
    This script will save and put purchases on leaderboard.
--]]


--[ SERVICES ]--

local DataStoreService = game:GetService("DataStoreService")
local DataStore = DataStoreService:GetDataStore("TimeStats")
local service = game:GetService("MarketplaceService")


--[ FUNCTIONS ]--

game.Players.PlayerAdded:Connect(function(Player) 
    --[{ LEADERSTATS }]--

    local Leaderstats = Instance.new("Folder")
    Leaderstats.Name = "leaderstats"
    Leaderstats.Parent = Player

    local Purchases = Instance.new("IntValue")
    Purchases.Name = "Purchases" -- changing name here (points, levels, time, etc.)
    Purchases.Value = 0 -- default value
    Purchases.Parent = Leaderstats

    local Minutes = Instance.new("IntValue") 
    Minutes.Name = "Minutes"
    Minutes.Value = 0 
    Minutes.Parent = Leaderstats


    --[{ DATA STORE }]--

    local Data = DataStore:GetAsync(Player.UserId) -- Get Data

    if type(Data) ~= "table" then
        Data = nil
    end

    if Data then
        Purchases.Value = Data.Purchases
    end




    local Data = DataStore:GetAsync(Player.UserId)
    if Data then
        Minutes.Value = Data
    end

    coroutine.resume(coroutine.create(function()
        while true do
            wait(60)
            Minutes.Value = Minutes.Value + 1
        end
    end))

end)

minute saving script :

-- [ SETTINGS ] --

local statsName = "Minutes" -- Your stats name
local maxItems = 100 -- Max number of items to be displayed on the leaderboard
local minValueDisplay = 1 -- Any numbers lower than this will be excluded
local maxValueDisplay = 10e15 -- (10 ^ 15) Any numbers higher than this will be excluded
local abbreviateValue = true -- The displayed number gets abbreviated to make it "human readable"
local updateEvery = 60 -- (in seconds) How often the leaderboard has to update
local headingColor = Color3.fromRGB(25, 181, 254) -- The background color of the heading

-- [ END SETTINGS ] --




-- Don't edit if you don't know what you're doing --

local DataStoreService = game:GetService("DataStoreService")
local Players = game:GetService("Players")
local DataStore = DataStoreService:GetOrderedDataStore("GlobalLeaderboard_" .. statsName)
local Frame = script.Parent.Frame
local Contents = Frame.Contents
local Template = script.objTemplate

local COLORS = {
    Default = Color3.fromRGB(38, 50, 56),
    Gold = Color3.fromRGB(255, 215, 0),
    Silver = Color3.fromRGB(192, 192, 192),
    Bronze = Color3.fromRGB(205, 127, 50)
}
local ABBREVIATIONS = { "K", "M", "B", "T" }


local function toHumanReadableNumber(num)
    if num < 1000 then
        return tostring(num)
    end

    local digits = math.floor(math.log10(num)) + 1
    local index = math.min(#ABBREVIATIONS, math.floor((digits - 1) / 3))
    local front = num / math.pow(10, index * 3)

    return string.format("%i%s+", front, ABBREVIATIONS[index])
end

local function getItems()
    local data = DataStore:GetSortedAsync(false, maxItems, minValueDisplay, maxValueDisplay)
    local topPage = data:GetCurrentPage()

    Contents.Items.Nothing.Visible = #topPage == 0 and true or false

    for position, v in ipairs(topPage) do
        local userId = v.key
        local value = v.value
        local username = "[Not Available]"
        local color = COLORS.Default

        local success, err = pcall(function()
            username = Players:GetNameFromUserIdAsync(userId)
        end)

        if position == 1 then
            color = COLORS.Gold
        elseif position == 2 then
            color = COLORS.Silver
        elseif position == 3 then
            color = COLORS.Bronze
        end

        local item = Template:Clone()
        item.Name = username
        item.LayoutOrder = position
        item.Values.Number.TextColor3 = color
        item.Values.Number.Text = position
        item.Values.Username.Text = username
        item.Values.Value.Text = abbreviateValue and toHumanReadableNumber(value) or value
        item.Parent = Contents.Items
    end
end


script.Parent.Parent.Color = headingColor
Frame.Heading.ImageColor3 = headingColor
Frame.Heading.Bar.BackgroundColor3 = headingColor

while true do
    for _, player in pairs(Players:GetPlayers()) do
        local leaderstats = player:FindFirstChild("leaderstats")

        if not leaderstats then
            warn("Couldn't find leaderstats!")
            break
        end

        local statsValue = leaderstats:FindFirstChild(statsName)

        if not statsValue then
            warn("Couldn't find " .. statsName .. " in leaderstats!")
            break
        end

        pcall(function()
            DataStore:UpdateAsync(player.UserId, function()
                return tonumber(statsValue.Value)
            end)
        end)
    end

    for _, item in pairs(Contents.Items:GetChildren()) do
        if item:IsA("Frame") then
            item:Destroy()
        end
    end

    getItems()

    wait()
    Frame.Heading.Heading.Text = statsName .. " Leaderboard"
    Contents.GuideTopBar.Value.Text = statsName
    wait(updateEvery)
end

but when the player joins the game for the first time his minute stat data saves but when he rejoins twice it somehow becomes less. for example, it's my first time joining the game, i played the game for 10 minutes then i had to go, so i join the next day and my minute stat is 10 which was the same as yesterday and I play the game for 5 minutes so my minute stat becomes 15, then i join the next day and my minute stat is 10. it didn't save my stat of the 2nd day, does anyone know how to figure this out??