Spectate script makes camera freeze in place?

I followed a tutorial for how to make a spectating script from a video on Youtube made one year ago(video maker is TheIceZombieSlayer Videos). Everything works fine, except every so often when I enter my game the camera gets stuck in one place and I cannot move it, while the rest of my game runs like normal(resetting does not help). It doesn't seem like anyone in the comment section of the video had the same problem I am having. I will paste my code below:

Player = game.Players.LocalPlayer
ScGUI = script.Parent
Camera = game.workspace.CurrentCamera
UIS = game:GetService("UserInputService")

Spectating = false
Index = 1

Camera.CameraSubject = Player.Character

function Watch(player)
    if player and player.Character and Camera.CameraSubject ~= player.Character then
        Camera.CameraSubject = player.Character
        ScGUI.SpectateFrame.TextLabel.Text = "*"..player.Name.."*"
    end
end

function ChangeState(bool)
    if bool == nil then
        Spectating = not Spectating
    else
        Spectating = bool
    end

    if Spectating then
        ScGUI.SpectateButton.Image = "rbxassetid://3376963769"
        ScGUI.SpectateFrame.Visible = true
    else
        Watch(Player)
        ScGUI.SpectateButton.Image = "rbxassetid://3364442186"
        ScGUI.SpectateFrame.Visible = false
    end
end


function CurrentCourse()
    return workspace.CurrentCourse:GetChildren()[1]
end

function IncrementIndex(num)
    local TempIndex = Index + num
    local Course = CurrentCourse()
    local TempContestants = Course.CourseInfo.TempContestants
    local Contestants = TempContestants:GetChildren()

    if TempIndex > #Contestants then
        TempIndex = 1
    elseif TempIndex < 1 then
        TempIndex = #Contestants
    end
    Index = TempIndex
end

ScGUI.SpectateButton.MouseButton1Click:connect(function ()
    ChangeState()
end)


UIS.InputBegan:connect(function (Input)
    if Input.KeyCode == Enum.KeyCode.Q then
        IncrementIndex(-1)
    elseif Input.KeyCode == Enum.KeyCode.E then
        IncrementIndex(1)
    end
end)

ScGUI.SpectateFrame.PreviousButton.MouseButton1Click:connect(function ()
    IncrementIndex(-1)
end)
ScGUI.SpectateFrame.NextButton.MouseButton1Click:connect(function ()
    IncrementIndex(1)
end)


game:GetService("RunService").RenderStepped:connect(function ()
    local Course = CurrentCourse()
    if Course then
        local TempContestants = Course:WaitForChild("CourseInfo"):WaitForChild("TempContestants")
        local Contestants = TempContestants:GetChildren()

        if not TempContestants:FindFirstChild(Player.Name) then
            ScGUI.SpectateButton.Visible = true
            if Spectating then
                IncrementIndex(0)
                Watch(Contestants[Index].Value)
            end
        else
            ScGUI.SpectateButton.Visible = false
            ChangeState(false)
        end
    else
        ScGUI.SpectateButton.Visible = false
        ChangeState(false)
    end
end)

Can someone please explain how I can fix this glitch?