My animation goes back to its original position?

Hello, I was working on a train door animation, When I played the animation, It goes back to its original position? Here is a video if you are confused: https://streamable.com/j6a0rs Code:

local model = script.Parent
local AnimationController = Instance.new("AnimationController", model)
local Animator = Instance.new("Animator", AnimationController)
local NewOpenAnim = Instance.new("Animation")
NewOpenAnim.AnimationId = "http://www.roblox.com/asset/?id=6708597628"

local NewCloseAnim = Instance.new("Animation")
NewCloseAnim.AnimationId = "http://www.roblox.com/asset/?id=6708599449"

local OpenAnim = Animator:LoadAnimation(NewOpenAnim)

local CloseAnim = Animator:LoadAnimation(NewCloseAnim)

OpenAnim:Play()