[UNSOLVED] Why is this GUI Shop Script Breaking the Weapons?

This GUI shop script works fine, other than the fact that when the gun is placed in your backpack, it's broken, with some parts no appearing, and it glitching your character's movement. However, upon resetting and equipping the tool again, the gun is fine.

And using admin commands to give a player a gun will not break it either, as the gun will be perfectly fine upon loading.

I have no idea why this is happening. Is there anyway to fix this issue without needing an external script?

Here's the script:

local Player = game.Players.LocalPlayer

script.Parent.MouseButton1Click:connect(function()
	if Player:findFirstChild("leaderstats") then
		if Player.leaderstats.Cash.Value >= tonumber(script.Parent.Cost.Value) then
			Player.leaderstats.Cash.Value = Player.leaderstats.Cash.Value-tonumber(script.Parent.Cost.Value)
			game.Lighting[script.Parent.ItemName.Value]:Clone().Parent=Player.Backpack
			game.Lighting[script.Parent.ItemName.Value]:Clone().Parent=Player.StarterGear
			wait(0.1)
			script:Destroy()
		end
	end
end)

while wait(0.1) do
	script.Parent.Text=tostring(script.Parent.ItemName.Value)..": $"..tonumber(script.Parent.Cost.Value)..""
end