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!