What's the current issue with the Data Module Script below?

local DefaultData = {["MultiplierLevel"] = 1, ["NetWorth"] = 0, ["Cash"] = 25, ["RobuxLevel"] = 0, ["TixLevel"] = 0, ["MoneybagLevel"] = 0, ["AutoClickerLevel"] = 0, ["HealthLevel"] = 0, ["DamageLevel"] = 0,["Colour"] = BrickColor.new("Really red"), ["Material"] = "Brick"}

print("Updated")
local PlayerStats = {}

local DataStore = game:GetService("DataStoreService")
local PlayerData = DataStore:GetDataStore("Data")

local Interval = 10

local CurrentData = {}
local LoadedPlayers = {}

function PlayerStats:IsPlayerLoaded(Player)
	local bool = LoadedPlayers[Player.Name] or false
	return bool
end

function PlayerStats.ChangeStat(Player, Stat, Value)
	if CurrentData[Player.Name] and CurrentData[Player.Name][Stat] then
		CurrentData[Player.Name][Stat] = Value
	else
		table.insert(CurrentData[Player.Name], Stat, DefaultData[Stat])
	end
	print(Value)
end

function PlayerStats.AddStat(Player, Stat, Value)
	if CurrentData[Player.Name] and CurrentData[Player.Name][Stat] then
		CurrentData[Player.Name][Stat] = CurrentData[Player.Name][Stat] + Value
	else
		table.insert(CurrentData[Player.Name], Stat, DefaultData[Stat])
	end
end
function PlayerStats.SubStat(Player, Stat, Value)
	if CurrentData[Player.Name] and CurrentData[Player.Name][Stat] then
		CurrentData[Player.Name][Stat] = CurrentData[Player.Name][Stat] - Value
	else
		table.insert(CurrentData[Player.Name], Stat, DefaultData[Stat])
	end
end

function PlayerStats.GetPlayerData(Player)
	return PlayerData:GetAsync(Player.UserId)
end

function PlayerStats.SetPlayerData(Player)
	if PlayerStats:IsPlayerLoaded(Player) then
		PlayerData:SetAsync(Player.UserId, CurrentData[Player.Name])
	end
end

function PlayerStats.ReturnCurrentData(Player, Stat)
	local dataTable = CurrentData[Player.Name]
	local data = DefaultData[Stat] or 0
	if dataTable ~= nil then data = dataTable[Stat] or DefaultData[Stat] end
	return data
end

local function NewPlayerData(Player)
	print("Player Joined")
	local Data = PlayerStats.GetPlayerData(Player)
	if not Data then
		CurrentData[Player.Name] = DefaultData
		PlayerStats.SetPlayerData(Player)
	else
		CurrentData[Player.Name] = Data
	end
	--CurrentData[Player.Name]["MultiplierLevel"], CurrentData[Player.Name]["NetWorth"], CurrentData[Player.Name]["Cash"], CurrentData[Player.Name]["RobuxLevel"], CurrentData[Player.Name]["TixLevel"], CurrentData[Player.Name]["MoneybagLevel"], CurrentData[Player.Name]["AutoClickerLevel"], CurrentData[Player.Name]["HealthLevel"], CurrentData[Player.Name]["DamageLevel"]
	LoadedPlayers[Player.Name] = true
	print(Player.Name, CurrentData[Player.Name]["MultiplierLevel"], CurrentData[Player.Name]["NetWorth"], CurrentData[Player.Name]["Cash"], CurrentData[Player.Name]["RobuxLevel"], CurrentData[Player.Name]["TixLevel"], CurrentData[Player.Name]["MoneybagLevel"], CurrentData[Player.Name]["AutoClickerLevel"], CurrentData[Player.Name]["HealthLevel"], CurrentData[Player.Name]["DamageLevel"])
	--print(Player.Name, CurrentData[Player.Name]["MultiplierLevel"], )
end

game.Players.PlayerAdded:Connect(function(Player)
	NewPlayerData(Player)
end)

function Autosave()
	--_G.NotifyPlayer("Server Notification", "Data Auto Saved", 5) --TESTING
	while wait(Interval) do
		for Player, Data in pairs(CurrentData) do
			PlayerStats.SetPlayerData(Player)
		end
	end
end

game.Players.PlayerRemoving:Connect(function(Player)
	PlayerStats.SetPlayerData(Player)
	CurrentData[Player.Name] = nil
end)

spawn(Autosave)

return PlayerStats

For some unknown reason, I seem to be getting no errors in the developer's log ingame, but in studio, I seem to be getting an API rejection issue. I have enabled access to the API for the script in configure game, but it doesn't seem to help. In addition to such, in both studio and ingame, it never actually saves the values. Instead it just comes back out with the old default values, which poses an issue.