Datastore Money Value is not saving correctly, any help?

I have this modified script mostly inspired by Youtube and it doesn't fully work. The Kills value saves perfectly, unlike the Money. What happens is that after a few hours to days, most of the total Money earned will reset or decrease about 80-90%. Being a nearly essential part of the game, I believe resetting the value will just erase everybody's total progress and possibly encounter the problem again. This is a trend in all players that exceed 1000 in cash. I currently have more than 2000 kills, and I should have three times the amount in cash, however my data just erased several times and I currently have about 450 Money.

As I got this tutorial on how to make it from YT, I am not sure how to troubleshoot or fix this.

Note: Money is gained from killing players and NPCs, and is used on things to buy. Kills are just collected.

local datastore = game:GetService("DataStoreService")
local ds1 = datastore:GetDataStore("MoneySaveSystem")
local ds2 = datastore:GetDataStore("KillsSaveSystem")

game.Players.PlayerAdded:Connect(function(plr)
	local folder = Instance.new("Folder", plr)
	folder.Name = "leaderstats"
	local money = Instance.new("IntValue", folder)
	money.Name = "Money"
	local kills = Instance.new("IntValue", folder)
	kills.Name = "Kills"
	
	money.Value = ds1:GetAsync(plr.UserId) or 0
	ds1:SetAsync(plr.UserId, money.Value)
	
	kills.Value = ds2:GetAsync(plr.UserId) or 0
	ds2:SetAsync(plr.UserId, kills.Value)
	
	money.Changed:connect(function()
		ds1:SetAsync(plr.UserId, money.Value)
	end)
	
	kills.Changed:connect(function()
		ds2:SetAsync(plr.UserId, kills.Value)
	end)
end)

game.Players.PlayerRemoving:Connect(function(player)
	local success, errormessage = pcall(function()
		ds1:SetAsync(player.UserId.."-money",player.leaderstats.Money.Value)
	end)
	
	if success then
		print ("Player Data successfully saved.")
	else
		print ("Error in saving Player Data.")
		warn (errormessage)
	end
end)

Quite simple fix, you just mixed up the keys.

local datastore = game:GetService("DataStoreService")
local ds1 = datastore:GetDataStore("MoneySaveSystem")
local ds2 = datastore:GetDataStore("KillsSaveSystem")

game.Players.PlayerAdded:Connect(function(plr)
    local folder = Instance.new("Folder", plr)
    folder.Name = "leaderstats"
    local money = Instance.new("IntValue", folder)
    money.Name = "Money"
    local kills = Instance.new("IntValue", folder)
    kills.Name = "Kills"

    money.Value = ds1:GetAsync(plr.UserId) or 0
    ds1:SetAsync(plr.UserId, money.Value)

    kills.Value = ds2:GetAsync(plr.UserId) or 0
    ds2:SetAsync(plr.UserId, kills.Value)

    money.Changed:connect(function()
        ds1:SetAsync(plr.UserId, money.Value)
    end)

    kills.Changed:connect(function()
        ds2:SetAsync(plr.UserId, kills.Value)
    end)
end)

game.Players.PlayerRemoving:Connect(function(player)
    local success, errormessage = pcall(function()
        ds1:SetAsync(player.UserId, player.leaderstats.Money.Value)
    end)

    if success then
        print ("Player Data successfully saved.")
    else
        print ("Error in saving Player Data.")
        warn (errormessage)
    end
end)

For the player removing, you had it as a different key than the player added.