leadrstats Stats not updating. What should i do?

If your button is on the player's screen, it's entirely clientside. This means that ONLY that player can see it, and ONLY that player can click it. This also means that any changes to leaderstats from that script will ONLY change for the player, and the server will not update. This is like editing a google doc while offline. While you can see the changes you've made, your friend cannot, and if you refresh the page you get the page that your friend is looking at. Let's see how you would fix this:

1. First thing's first, we need to make leaderstat changes occur in a serverside script, so let's place a Script in game.ServerScriptStorage.

2. In order for the LocalScript to communicate to the Server, we need to add a RemoteFunction to game.ReplicatedStorage. Let's name it "tryToPurchase".

This is the LocalScript inside the player's GUI

local buyButton = script.Parent
local newSpaces = 1000000
local upgradeCost = 100000000
--//This is fine, just declaring variables

local function giveUpgrade()
	--//We do not need to check who clicked the button, since the player is passed automatically through the RemoteFunction
	game.ReplicatedStorage.tryToPurchase:Invoke(upgradeCost, newSpaces)
	--//We shouldn't make changes to leaderstats locally, so we invoke the RemoteFunction we created earlier.
end

script.Parent.Activated:Connect(giveUpgrade)

This is the Script in game.ServerScriptStorage

game.ReplicatedStorage.tryToPurchase.OnServerInvoke = function(player, cost, spaces)
	--//We link this function to when tryToPurchase is invoked.
	--//We create parameters for the upgradeCost and newSpaces passed along. The player who invoked the function is a hidden parameter, and we need to declare it.

	local playerStats = player:FindFirstChild("leaderstats")
	local playerGold = playerStats:FindFirstChild("Gold")
	local playerSpaces = playerStats:FindFirstChild("Spaces")
	--//Now we can actually calculate the purchase.

	if playerGold.Value >= upgradeCost then
		playerGold.Value = playerGold.Value - cost
		playerSpaces.Value = spaces
	end
end