My Zipline is extremely laggy, why?

Hello, my fellow scripters and game developers, I am making a game of ziplining, but when I use it, my character rapidly spins and lags, though it still moves the player? what can I do to fix this, i would love some help, thank you, here is the code.

local TweenService = game:GetService("TweenService")

function onTouched(Obj)
    local h = Obj.Parent:FindFirstChild("HumanoidRootPart")
    if h then
        local playertween = TweenService:Create(
            h,
            TweenInfo.new(2, Enum.EasingStyle.Quart, Enum.EasingDirection.InOut, 0.5, false, 0),
            {CFrame = script.Parent.Parent.wha.CFrame}
        )
        playertween:Play()
    end
end

script.Parent.Touched:Connect(onTouched)