Why is my tool in the starterpack not go to the player backpack?

Hello,

I am having an issue in my roblox game where the tool I have is not going into my backpack. I have it in starterpack, and I have a custom hotbar system. When the game loads, I can see that it is in my backpack, but it is not in my custom hotbar. Here is a video that may help you understand my issue:

https://vimeo.com/546690125

Also, here is my Hotbar Script:

--// Variables
local plr = game.Players.LocalPlayer
local UI = script.Parent
local MainFrame = UI.MainFrame
local StrNum = {["One"] = "1", ["Two"] = "2", ["Three"] = "3", ["Four"] = "4", ["Five"] = "5", ["Six"] = "6", ["Seven"] = "7", ["Eight"] = "8", ["Nine"] = "9"}
local SlotData = {
	CurrentSlot = nil,
	Slots = {
		["Slot1"] = {Equipped = false, CurrentTool = false, Index = 1},
		["Slot2"] = {Equipped = false, CurrentTool = false, Index = 2},
		["Slot3"] = {Equipped = false, CurrentTool = false, Index = 3},
		["Slot4"] = {Equipped = false, CurrentTool = false, Index = 4},
		["Slot5"] = {Equipped = false, CurrentTool = false, Index = 5},
		["Slot6"] = {Equipped = false, CurrentTool = false, Index = 6},
		["Slot7"] = {Equipped = false, CurrentTool = false, Index = 7},
		["Slot8"] = {Equipped = false, CurrentTool = false, Index = 8},
		["Slot9"] = {Equipped = false, CurrentTool = false, Index = 9}
	}
}

--// Disable Default Hotbar
game.StarterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack, false)

--// Functions
function getNextEmptySlot()
	local possibleSlots = {}
	for i, v in pairs(SlotData.Slots) do
		if v.CurrentTool == false then
			table.insert(possibleSlots, v)
		end
	end
	local function lowestNumber()
		local low = 10 --// Add num
		for i, v in pairs(possibleSlots) do
			if v.Index < low then
				low = v.Index
			end
		end
		return low
	end
	local num = tostring(lowestNumber())
	if num ~= nil then
		return SlotData.Slots["Slot"..num]
	else
		return nil
	end
end
function updateSlots()
	for i, v in pairs(SlotData.Slots) do
		local uiSlot = MainFrame:FindFirstChild("Slot"..tostring(v.Index))
		uiSlot.SlotName.TextColor3 = Color3.fromRGB(255, 255, 255)
		uiSlot.bg.ImageColor3 = Color3.fromRGB(46, 46, 46)
		uiSlot.ToolName.TextColor3 = Color3.fromRGB(255, 255, 255)
		if v.CurrentTool == false then
			uiSlot.ToolName.Text = ""
		elseif v.CurrentTool ~= false then
			uiSlot.ToolName.Text = v.CurrentTool.Name
			if v.CurrentTool.Parent ~= plr.Character and v.CurrentTool.Parent ~= plr.Backpack then
				uiSlot.ToolName.Text= ""
				v.Equipped = false
				v.CurrentTool = false
			end
		end
		if v.Equipped == true then
			uiSlot.SlotName.TextColor3 = Color3.fromRGB(0, 170, 255)
			uiSlot.bg.ImageColor3 = Color3.fromRGB(255, 255, 255)
			uiSlot.ToolName.TextColor3 = Color3.fromRGB(46, 46, 46)
		end
	end
end
function equipSlot(slot_num)
	local done = false
	local Slot = SlotData.Slots["Slot"..slot_num]
	local uiSlot = MainFrame:FindFirstChild("Slot"..slot_num)
	if done == false then
		done = true
		if Slot.Equipped == false then
			for i, v in pairs(MainFrame:GetChildren()) do if v.ClassName == "ImageButton" then v.SlotName.TextColor3 = Color3.fromRGB(255, 255, 255) v.bg.ImageColor3 = Color3.fromRGB(46, 46, 46) v.ToolName.TextColor3 = Color3.fromRGB(255, 255, 255) end end
			for i, v in pairs(plr.Character:GetChildren()) do if v:IsA("Tool") and v~= Slot.CurrentTool then wait() v.Parent = plr.Backpack end end
			for i, v in pairs(SlotData.Slots) do v.Equipped = false end
			SlotData.Current = Slot
			Slot.Equipped = true
			if Slot.CurrentTool ~= false then
				Slot.CurrentTool.Parent = plr.Character
				uiSlot.ToolName.Text = Slot.CurrentTool.Name
			end
			--uiSlot.SlotName.TextColor3 = Color3.fromRGB(0, 170, 255) // Test
			--uiSlot.bg.ImageColor3 = Color3.fromRGB(255, 255, 255)
			--uiSlot.ToolName.TextColor3 = Color3.fromRGB(46, 46, 46)
			updateSlots()
			wait(.2)
			done = false
		elseif Slot.Equipped == true then
			for i, v in pairs(MainFrame:GetChildren()) do if v.ClassName == "ImageButton" then v.SlotName.TextColor3 = Color3.fromRGB(255, 255, 255) v.bg.ImageColor3 = Color3.fromRGB(46, 46, 46) v.ToolName.TextColor3 = Color3.fromRGB(255, 255, 255) end end
			for i, v in pairs(plr.Character:GetChildren()) do if v:IsA("Tool") then wait() v.Parent = plr.Backpack end end
			for i, v in pairs(SlotData.Slots) do v.Equipped = false end
			SlotData.CurrentSlot = nil
			wait(.2)
			done = nil
		end
	end
end

for i, v in pairs(MainFrame:GetChildren()) do
	if v.ClassName == "ImageButton" then
		v.MouseButton1Click:Connect(function()
			equipSlot(v.Name:sub(5))
			updateSlots()
		end)
	end
end
game:GetService("UserInputService").InputBegan:Connect(function(key)
	for i, v in pairs(StrNum) do
		if key.KeyCode == Enum.KeyCode[i] then
			if MainFrame:FindFirstChild("Slot"..v) then
				equipSlot(v)
				updateSlots()
			else
				print("Slot"..v, "Does not exist")
			end
		end
	end
	if key.KeyCode == Enum.KeyCode.Backspace then
		if SlotData.CurrentSlot ~= nil then
			updateSlots()
		end
	end
end)
plr.Backpack.ChildAdded:Connect(function(newChild)
	for a, b in pairs(SlotData.Slots) do
		if b.CurrentTool == newChild then
			return
		end
	end
	local Slot = getNextEmptySlot()
	if Slot ~= nil then
		Slot.CurrentTool = newChild
		equipSlot(tostring(Slot.Index))
		updateSlots()
	end
end)
plr.Character.ChildAdded:Connect(function(newChild)
	if newChild:IsA("Tool") then
		for a, b in pairs(SlotData.Slots) do
			if b.CurrentTool == newChild then
				return
			end
		end
		local Slot = getNextEmptySlot()
		if Slot ~= nil then
			Slot.CurrentTool = newChild
			equipSlot(tostring(Slot.Index))
			updateSlots()
		else
			newChild.Parent = workspace
		end
	end
end)

Please help if you can.

Thanks!