When i put the datasaving leaderboard with my shop buy script, works in studio but not in-game?

So i have this datasaving leaderboard and shop GUI script, works fine in studio but not in-game. heres the script:

DataStoreService = game:GetService("DataStoreService")
CashDS = DataStoreService:GetDataStore("CashDS")
Event = game.ReplicatedStorage.Minus
local shop = game.Workspace.Shop
local tool = game.ReplicatedStorage:WaitForChild("Tools")
game.Players.PlayerAdded:connect(function(plr)
Shopping = plr.PlayerGui:WaitForChild('Shop')
end)

function FunctionNameHere(player, key)
if player:WaitForChild("leaderstats")["????Cash"].Value >= shop:FindFirstChild("Part" .. Shopping.Item.Value).ItemPrice.Value then
        if player.Backpack:FindFirstChild(shop:FindFirstChild("Part" .. Shopping.Item.Value).ItemName.Value) == nil then
            if shop:FindFirstChild("Part" .. Shopping.Item.Value) then
            local playerKey = key
               player:WaitForChild("leaderstats")["????Cash"].Value = player.leaderstats["????Cash"].Value - shop:FindFirstChild("Part" .. Shopping.Item.Value).ItemPrice.Value
                wait()
                CashDS:SetAsync(playerKey, player.leaderstats["????Cash"].Value)
                Shopping.Frame.Buy.Text = "Bought"
                Shopping.Frame.Buy.BackgroundColor3 = Color3.new(0.7,0.7,0.7)
                Shopping.Frame.Buy.Shadow.BackgroundColor3 = Color3.new(0.5,0.5,0.5)
                game.ReplicatedStorage.ShopBuy:FireServer(Shopping.Item.Value)              

            end
        end

    end
end


Event.OnServerEvent:Connect(FunctionNameHere)

the datasaving leaderboard script:

local DataStoreService = game:GetService("DataStoreService")
local CashDS = DataStoreService:GetDataStore("CashDS")

game.Players.PlayerAdded:connect(function(player)
    local leader = Instance.new("Folder",player)
    leader.Name = "leaderstats"
    local Cash = Instance.new("IntValue",leader)
    Cash.Name = "????Cash"
    Cash.Value = CashDS:GetAsync(player.Name) or 0
end)

game.Players.PlayerRemoving:connect(function(player)
    CashDS:UpdateAsync(player.Name, function(oldValue) return player.leaderstats["????Cash"].Value end)
end)

game.OnClose = function()
    for i,v in pairs(game.Players:GetChildren()) do
        CashDS:UpdateAsync(v.Name, function(oldValue) return v.leaderstats["????Cash"].Value end)
    end
    wait(1)
end

Can someone explain to me what the problem is and how to fix it?