Datastore not working anymore, can someone explain please?

It was working fine yesterday and days before then, I just tested it today and now it doesn't save anything. It also gives off no errors in the output.

local DataStore = game:GetService("DataStoreService")
local ds = DataStore:GetDataStore("LeaderboardSaveSystem")
local Players = game:GetService("Players")


Players.PlayerAdded:Connect(function(player) 
    local key = tostring(player.UserId) 
    local data = ds:GetAsync(key) 
    local leader = Instance.new("Folder") 
    leader.Name = "leaderstats"
    leader.Parent = player 
    local Speed = Instance.new("NumberValue", leader)
    Speed.Name = "Speed"
    local Rebirth = Instance.new("NumberValue", leader)
    Rebirth.Name = "Rebirth"
	local GemVal = Instance.new("NumberValue", player)
	GemVal.Name = "GemVal"
	local Purchase1 = Instance.new("BoolValue", player)
	Purchase1.Name = "RedTrail"
    local success, msg = pcall(function() 
        if data then  
            Speed.Value = data[1]
            Rebirth.Value = data[2]
			GemVal.Value = data[3]
			Purchase1.Value = data[4]
        else 
            Speed.Value = 0 
            Rebirth.Value = 0
			GemVal.Value = 0
			Purchase1.Value = false
        end
    end)
end) 


Players.PlayerRemoving:Connect(function(player)
    local data = {  
        player.leaderstats.Speed.Value,
        player.leaderstats.Rebirth.Value,
		player.GemVal.Value,
		player.Purchase1.Value
    }

    local key = tostring(player.UserId)
    print("player left:", player)
    ds:SetAsync(key, data)
end)