how can I change my local script to fit this datastore?

I'm pretty sure this is the problem. I made a datastore script that goes like this:

local DataStoreService = game:GetService("DataStoreService")
local MyDataStore = DataStoreService:GetDataStore("myDataStore")


game.Players.PlayerAdded:Connect(function(player)

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

    -- Display an 'IntValue' on leaderboard
    local cash = Instance.new("IntValue")
    cash.Name = "Cash"
    cash.Parent = leaderstats





    local data
    local success, errormessage = pcall(function()

         data = MyDataStore:GetAsync(player.UserId.."-cash") or 0
    end)


    if success then

        cash.Value = data
    else
            print("error")
            warn(errormessage)
    end
end)






game.Players.PlayerRemoving:Connect(function(player)
    local success, errormessage = pcall(function()
    MyDataStore:SetAsync(player.UserId.."-cash",player.leaderstats.Cash.Value) 

    end)
    if success then print("Data Saved")
        else print("error")
            warn("errormessage")

    end





end)

If I play my game on Roblox (not studio) I am able to save the value of cash if I type a command from HD admin.

Change me Cash 1000

I leave the game and this is saved and remains when I come back. However, I have a localscript in StarterPlayerScripts that is:

while true do
 wait(10)
game.Players.LocalPlayer.leaderstats.Cash.Value = game.Players.LocalPlayer.leaderstats.Cash.Value + 10
  end

The 1000 will go (ex.1040) and it won't save.
I can use the admin command to change the value to 1040 and it saves. What can I do to fix this?