datastore not functioning, right after it loads it turns to zero?

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#Problem

It's supposed to work like a normal datastore, but obviously things never work for me so there was something wrong; When my friend joined, i saw his old datastore go to his for a split second and then it went back to zero for a reason?

#Script

local DataStoreService = game:GetService("DataStoreService")
local StatsData = DataStoreService:GetDataStore("Savers")

local key = "Player_"

game.Players.PlayerAdded:Connect(function(player)
	local sucess, errormessage = pcall(function()
		local retrievedData = StatsData:GetAsync(key .. player.UserId)
		local leaderstats = player.leaderstats
		
		leaderstats.Cash.Value = retrievedData[1]
		leaderstats.Power.Value = retrievedData[2]
		leaderstats.Rebirths.Value = retrievedData[3]
	end)
end)

game.Players.PlayerRemoving:Connect(function(player)
	
	local leaderstats = player.leaderstats
	
	local sucess, errormessage = pcall(function()
		StatsData:SetAsync(key .. player.UserId, {leaderstats.Cash.Value, leaderstats.Power.Value, leaderstats.Rebirths.Value})
	end)
	
	if sucess then
		print("Was a succesfull data store!")
	else
		warn(errormessage)
	end
end)