Why Does The Datastore Fail?

Help and Feedback Scripting Support
,
#1

Whenever I change the value server-side and leave the game, the data isn’t saved. How come?

Script 
local DataStoreService = game:GetService("DataStoreService")
local playerData = DataStoreService:GetDataStore("PlayerData")

function onPlayerJoin(player)  -- Runs when players join
	local Interests = Instance.new("Folder")  --Sets up leaderstats folder
	Interests.Name = "Interests"
	Interests.Parent = player

	local Interest1 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest1.Name = "Interest1"
	Interest1.Parent = Interests

	local Interest2 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest2.Name = "Interest2"
	Interest2.Parent = Interests

	local Interest3 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest3.Name = "Interest3"
	Interest3.Parent = Interests

	local Interest4 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest4.Name = "Interest4"
	Interest4.Parent = Interests

	local Interest5 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest5.Name = "Interest5"
	Interest5.Parent = Interests

	local Interest6 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest6.Name = "Interest6"
	Interest6.Parent = Interests

	local Interest7 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest7.Name = "Interest7"
	Interest7.Parent = Interests

	local Interest8 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest8.Name = "Interest8"
	Interest8.Parent = Interests

	local Interest9 = Instance.new("StringValue") --Sets up value for leaderstats
	Interest9.Name = "Interest9"
	Interest9.Parent = Interests

	local playerUserId = tostring(player.UserId).."-Interests"  --Gets player ID
	local data = playerData:GetAsync(playerUserId)  --Checks if player has stored data
	if data then
		Interest1.Value = data['Interest1']
		Interest2.Value = data['Interest2']
		Interest3.Value = data['Interest3']
		Interest4.Value = data['Interest4']
		Interest5.Value = data['Interest5']
		Interest6.Value = data['Interest6']
		Interest7.Value = data['Interest7']
		Interest8.Value = data['Interest8']
		Interest9.Value = data['Interest9']
	else
		-- Data store is working, but no current data for this player
		Interest1.Value = "None"
		Interest2.Value = "None"
		Interest3.Value = "None"
		Interest4.Value = "None"
		Interest5.Value = "None"
		Interest6.Value = "None"
		Interest7.Value = "None"
		Interest8.Value = "None"
		Interest9.Value = "None"
	end
end

function create_table(player)
	local player_stats = {}
	for _, stat in pairs(player.Interests:GetChildren()) do
		player_stats[stat.Name] = stat.Value
	end
	return player_stats
end

function onPlayerExit(player)  --Runs when players exit

	local player_stats = create_table(player)
	local success, err = pcall(function()
		local playerUserId = tostring(player.UserId).."-Interests"
		playerData:SetAsync(playerUserId, player_stats) --Saves player data
	end)

	if not success then
		warn('Could not save data!')
	end
end

game.Players.PlayerAdded:Connect(onPlayerJoin)
game.Players.PlayerRemoving:Connect(onPlayerExit)
#2

Is this being done in a live game? If so, you need bind to close, which should look like this:

game:BindToClose(function()
    if game:GetService("RunService"):IsStudio() then return end
    for _, player in (game:GetService("Players")) do
        task.spawn(onPlayerExit, player)
    end
end)

Unrelated to the issue, but using SetAsync is a pretty bad idea in general.