This code does not save data correctly?

I am trying to save playerdata but the issue is, is that, this code, if someone leaves, while I am playing, when they rejoin, they end up with my stats. It seems when they are leaving the data is saved for the wrong player. How can I fix this? If only I can connect an event when a SPECIFIC player is leaving. Like game.Players.asadefa.Removing:Connect()

The following code is in a PlayerAdded:Connect() function

        local ChangeData = Instance.new("BindableFunction", BFuncionsF)
    ChangeData.Name = Player.UserId
    local S, Data = pcall(function()
        local Data = Database:GetAsync("USER"..Player.UserId) or {}
        local DataTable = {
            ['IsOP'] = Data['IsOP'] or 0,
            ['Level'] = Data['Level'] or 0,
            ['LvlXP'] = Data['LvlXP'] or 0,
            ['Money'] = Data['Money'] or 0,
            ['Crystal'] = Data['Crystal'] or 0,
            ['Bonker'] = Data['Bonker'] or 0,
            ['Sword'] = Data['Sword'] or 0,
            ['Hammer'] = Data['Hammer'] or 0,
            ['Knife'] = Data['Knife'] or 0,
            ['Brick'] = Data['Brick'] or 0,
            ['NeutronHammer'] = Data['NeutronHammer'] or 0,
            ['DraviteHammer'] = Data['DraviteHammer'] or 0,
            ['SpellPower'] = Data['SpellPowerSpells'] or 0,
            ['FireSpells'] = Data['FireSpells'] or 0,
            ['IceSpells'] = Data['IceSpells'] or 0
        }
        return DataTable
    end)
    AllocateItems(Data, Player)
    local Leaderstats = Instance.new("BoolValue", Player)
    Leaderstats.Name = "leaderstats"
    local Level = Instance.new("IntValue", Leaderstats)
    Level.Name = "Level"
    Level.Value = Data['Level']
    local Money = Instance.new("IntValue", Leaderstats)
    Money.Name = "Money"
    Money.Value = Data['Money']
    local Crystals = Instance.new("IntValue", Leaderstats)
    Crystals.Name = "Crystals"
    Crystals.Value = Data['Crystal']
    ChangeData.OnInvoke = function(Type, Value)
        Data[Type] = Value
        if Type == Level.Name then
            Level.Value = Value
        elseif Type == Money.Name then
            Money.Value = Value
        elseif Type == Crystals.Name then
            Crystals.Value = Value
        end
    end
    game:GetService("Players").PlayerRemoving:Connect(function(Player)
        Database:SetAsync("USER"..Player.UserId, Data)
    end)