Clones to the hit.Parent, another player touches it, they get but other loses it, why?

local model = script.Parent
local toucher = model.Detector
local label = model.Display.SurfaceGui.Status
local screen = model.Display
local BillboardGui = Instance.new("BillboardGui")
local Text = Instance.new("TextBox")

local inuse = false

toucher.Touched:Connect(function(hit)
    if game.Players:GetPlayerFromCharacter(hit.Parent) and not inuse and not hit.Parent.Head:FindFirstChildOfClass("BillboardGui") then
        inuse = true
        local player = game.Players:GetPlayerFromCharacter(hit.Parent)
        for i = 0, 0 do
            label.Text = 'AUTHORIZING'
            label.TextColor3 = Color3.fromRGB(255, 239, 201)
            screen.Warning.PlaybackSpeed = 2.3
            script.Parent.Display.Color = Color3.fromRGB(255, 239, 201)
            model.Glow.Color = Color3.fromRGB(255, 239, 201)
            model.Glow.PointLight.Color = Color3.fromRGB(255, 239, 201)
            screen.Warning:Play()
            wait(0.3)
            label.Visible = false
            wait(0.65)
            label.TextColor3 = Color3.fromRGB(255, 239, 201)
            script.Parent.Display.Color = Color3.fromRGB(255, 239, 201)
            model.Glow.Color = Color3.fromRGB(255, 239, 201)
            model.Glow.PointLight.Color = Color3.fromRGB(255, 239, 201)
            label.Text = 'AUTHORIZING'
            screen.Warning.PlaybackSpeed = 2.3
            screen.Warning:Play()
            wait(0.3)
            label.Visible = false
            wait(0.65)
            screen.Stab:Play()
        end
        wait(1)
            label.Visible = true
            screen.Warning.PlaybackSpeed = 4
            label.TextColor3 = Color3.fromRGB(107, 255, 66)
            script.Parent.Display.Color = Color3.fromRGB(0, 255, 0)
            model.Glow.Color = Color3.fromRGB(0, 255, 0)
            model.Glow.PointLight.Color = Color3.fromRGB(0, 255, 0)
            ----GUI
            label.Text = 'NANOCHIP INJECTED'
            BillboardGui.Name = "AuthorizeTag"
            BillboardGui.Parent = hit.Parent:WaitForChild("Head")
            BillboardGui.Active = true
            BillboardGui.Adornee = hit.Parent:WaitForChild("Head")
            BillboardGui.Size = UDim2.new(40, 40, 1, 1)
            BillboardGui.StudsOffset = Vector3.new(0, 3, 0)

            Text.Name = "Text"
            Text.Parent = BillboardGui
            Text.BackgroundColor3 = Color3.new(0, 0, 0)
            Text.BackgroundTransparency = 1
            Text.BorderColor3 = Color3.new(0, 0, 0)
            Text.Size = UDim2.new(1, 1, 0.699999988, 0)
            Text.ClearTextOnFocus = false
            Text.Font = Enum.Font.SourceSans
            Text.MultiLine = true
            Text.Text = "AUTHORIZED | " .. hit.Parent.Name
            Text.TextColor3 = Color3.new(0.517647, 1, 0)
            Text.TextScaled = true
            Text.TextSize = 14
            Text.TextStrokeColor3 = Color3.new(1, 1, 1)
            Text.TextWrapped = true
            Text.TextYAlignment = Enum.TextYAlignment.Top
            ----GUI
            screen.Warning:Play()
            wait(0.25)
            screen.Warning:Play()
            wait(0.25)
            screen.Warning:Play()
        end
        wait(5)
        inuse = false
    end)

This is used to mark players, but whenever they touch it, a billboard gui gets created which is intended. But if I do it to someone else, the player who touched it before loses the tag, and the new player gets it. What's the problem?