My Inventory is not updating properly?

Hello!

I'm having trouble with my Custom Inventory system. It randomly decides to delete the items inside the Backpack...which is not good. There doesn't appear to be any rhyme or reason as to why - sometimes the items remain in the backpack if a player leaves/returns, sometimes it doesn't. The only real output I get is to say I have Backpack mislabeled? But it still functions...except for retaining the items of course.

How do I fix this?

Any help is very much appreciated. Thanks!

Below is inside a local script within my screen GUI.

local player = game.Players.LocalPlayer

local StarterGui = game:GetService('StarterGui')
StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack, false)

local Enabled = false

player.CharacterAdded:wait() 
function UpdateInventory()
    if Enabled == false then
        Enabled = true
        script.Parent.Frame.Visible = true
        script.Parent.Frame.CanvasSize = UDim2.new(0,0,0,20*#player.Backpack:children())
        script.Parent.Frame:ClearAllChildren()
        for i,v in pairs(player.Backpack:GetChildren()) do
            local Obj1 = Instance.new('TextButton',script.Parent.Frame)
            Obj1.Size = UDim2.new(1,-12,0,20)
            Obj1.Position = UDim2.new(0,0,0,20*i-20)
            Obj1.BackgroundTransparency = 1
            Obj1.FontSize = 'Size24'
            Obj1.Text = v.Name
            Obj1.Font = 'SourceSansBold'
            Obj1.TextColor3 = Color3.new(255,255,255)
            Obj1.TextXAlignment = 'Left'
            Obj1.MouseButton1Down:connect(function()
                player.Character.Humanoid:UnequipTools()
                player.Character.Humanoid:EquipTool(v)
            end)
        end
    else
        Enabled = false
        script.Parent.Frame.Visible = false
    end
end

script.Parent.InvenButton.MouseButton1Down:connect(function()
    UpdateInventory()
end)

-- BELOW

script.Parent.ImageButton.MouseButton1Down:connect(function()
    UpdateInventory()
end)

-- ABOVE

player.Backpack.Changed:connect(function()
    if Enabled == false then Enabled = true UpdateInventory() end
    if Enabled == true then Enabled = false UpdateInventory() end
end)