Datastore2 not saving if values decrease?

For some reason when I raise the values it saves, but if I lower them they don't. idk what to do so plz help. Also, it won't save the weapons value for some reason too, and its a string value.

local DataStore2 = require(1936396537)

DataStore2.Combine("MasterKey", "Yuan", "Kills", "Weapon")

game.Players.PlayerAdded:Connect(function(plr)
	
	local yuanData = DataStore2("Yuan", plr)
	local killsData = DataStore2("Kills", plr)
	local weaponData = DataStore2("Weapon", plr)
	
    local leaderstats = Instance.new("Folder", plr)
    leaderstats.Name = "Stats"
 
    local yuan = Instance.new("IntValue", leaderstats)
    yuan.Name = "Yuan"
	local kills = Instance.new("IntValue", leaderstats)
	kills.Name = "Kills"
	local weapon = Instance.new("StringValue", leaderstats)
	weapon.Name = "Weapon"

	if yuanData:Get() ~= nil then
    	yuan.Value = yuanData:Get()
	else
		yuan.Value = 0
	end
	if killsData:Get() ~= nil then
    	kills.Value = killsData:Get()
	else
		kills.Value = 0
	end
	if weaponData:Get() ~= nil then
		weapon.Value = weaponData:Get()
	else
		weapon.Value = "None"
	end
	
	yuan.Changed:connect(function()
		yuanData:Set(yuan.Value)
		print("yuan success")
	end)
	kills.Changed:connect(function()
		killsData:Set(kills.Value)
		print("kills success")
	end)
	weapon.Changed:connect(function()
		weaponData:Set(weapon.Value)
		print("weapon success")
	end)
end)