UpdateAsync Broke After Changing Something? [SOLVED]

So, I've been looking for answers all over for days on end. I haven't been able to find anything new for a while now, so I think asking a question here is my last option.

I've changed values around, I've changed the structure of the code, I've changed how the script accesses the values. But with no success. It did work at one point, but I needed to change it and now I can't remember for the life of me what I did.

If anyone can help, it would be greatly appreciated, here is the code:

local dataStoreService = game:GetService("DataStoreService")
local StatStore = dataStoreService:GetDataStore("StatStore")

game.Players.PlayerAdded:Connect(function(player)
	game.Workspace:WaitForChild(player.Name)
	player:WaitForChild("leaderstats")
	
	local Key = player.UserId
	
	local Leaderstats = player.leaderstats
	local Steps = Leaderstats.Steps
	local SpeedBoost = player.PlayerGui.Codes.SpeedBoost
	
	local DefaultData = {
		["Steps"] = 0,
		["SpeedBoost"] = false
	}
	
	local Stats
	local recieved, notRecieved = pcall(function()
		Stats = StatStore:GetAsync(Key) or DefaultData
	end)
	
	if recieved then
		Steps.Value = Stats
		SpeedBoost.Value = Stats
		print("Stats were recieved")
	else
		StatStore:SetAsync(Key, DefaultData)
		print("Stats were not recieved")
		warn(notRecieved)
	end
	
	wait(0.1)
	
	local Stats = {
		["Steps"] = Leaderstats.Steps.Value,
		["SpeedBoost"] = player.PlayerGui.Codes.SpeedBoost.Value
	}
	
	while wait(300) do
		local saved, notSaved = pcall(function()
			StatStore:UpdateAsync(player.UserId, function(oldValue)				
				print("Stats were auto saved!")
				
				return Stats
			end)
		end)
	end
end)


game.Players.PlayerRemoving:Connect(function(player)
	local User = game.Players:FindFirstChild(player.Name)
	
	local Leaderstats = User.leaderstats
	local NewSteps = script.Parent.StepLoop.Steps
	local Steps = Leaderstats.Steps
	local SpeedBoost = User.PlayerGui.Codes.SpeedBoost
	
	local DefaultData = {
		["Steps"] = 0,
		["SpeedBoost"] = false
	}
	
	local Key = User.UserId
	
	local Stats = {
		["Steps"] = Leaderstats.Steps.Value,
		["SpeedBoost"] = User.PlayerGui.Codes.SpeedBoost.Value
	}
	
	local success, result = pcall(function()
    	StatStore:UpdateAsync(Key, function(oldValue)
			return Stats
    	end)
	end)
	
	if success then
		print("Stats were saved")
	else
		print("Stats were not saved")
		warn(result)
	end
end)

(SpeedBoost is a Bool value and Steps is an Int value)

I eventually figured this out, so for anyone else that might have this problem, make sure the tables are single values.

Example:

--Instead of:
Stats = {
	["Steps"] = Leaderstats.Steps.Value,
	["SpeedBoost"] = SpeedBoost.Value
}

--do:
Stats = {
	Leaderstats.Steps.Value,
	SpeedBoost.Value
}

Also, I found that PlayerGui gets removed before the player a lot, it's not at the same time. So just make sure you aren't trying to access values that are in the PlayerGui, an easy way around this is to just change where they're located.

When getting data, do:

Steps.Value = Stats[1]
--Not:
Steps.Value = Stats

The [1] after Stats, is the first value in the Stats table, so for SpeedBoost you would just do Stats[2] because it's the second value in the Stats table.