The data storing system doesn't save the data when the player leaves the game, any ideas why?

Here's the script:

local DataBaseStore = game:GetService("DataStoreService"):GetDataStore("AllTheStatsAreHere")
local Statsholder = script.Stats
local players = game:GetService("Players")


players.PlayerAdded:Connect(function(NewPlayer)
	
	local key = "Player-ID:" .. NewPlayer.UserId
	local GetSave = DataBaseStore:GetAsync(key)
	
	local DataBaseFolder = Instance.new("Folder", NewPlayer)
	DataBaseFolder.Name = "PlayerStats"
	
	for i, Stats in pairs(Statsholder:GetChildren()) do
		local NewStats = Instance.new(Stats.ClassName)
		NewStats.Name = Stats.Name
		NewStats.Value = Stats.Value
		NewStats.Parent = DataBaseFolder
	end
	
	if GetSave then
		
		for i, Stats in pairs(script.Stats:GetChildren()) do
			
			DataBaseFolder[Stats.Name].Value = GetSave[i]
			print(i, Stats.Name, Stats.Value)
			
			end
			
	else -- Save Stats
		
		local StatsToSave = {}
			
			for i, Stats in pairs(DataBaseFolder:GetChildren()) do
				
				table.insert(StatsToSave, Stats.Value)
				print(i, Stats.Name, Stats.Value)
				
			end
			
			DataBaseStore:SetAsync(key, StatsToSave)
			
	
		end
		
		while wait(15) do  --Autosave
			
			local StatsToSave = {}
			
			for i, Stats in pairs(DataBaseFolder:GetChildren()) do
				
				table.insert(StatsToSave, Stats.Value)
				print(i, Stats.Name, Stats.Value)
				
			end
			
			DataBaseStore:SetAsync(key, StatsToSave)
			
		end
		
		players.PlayerRemoving:Connect(function(OldPlayer)
			
			
			local key = "Player-ID:" .. OldPlayer.UserId
			
			local StatsToSave = {}
			
			for i, Stats in pairs(DataBaseFolder:GetChildren()) do
				
				table.insert(StatsToSave, Stats.Value)
				print(i, Stats.Name, Stats.Value)
				
			end
			
			DataBaseStore:SetAsync(key, StatsToSave)
			
		end)
		
		
end)

So technically the script should save those stats as the player is leaving since the output displays no errors. It does save every 15 seconds, but doesn't when the player leaves. Any ideas how could this get fixed?