Why does the CFrame animation teleport?

for i = 0.001, 0.1, 0.001 do
	game.Workspace.Door.CFrame = game.Workspace.Door.CFrame * CFrame.new(Vector3.new(0,0.1,0))
	wait() 
	end
	end
	
	wait(5)
	
	for i = 0.001, 0.1, 0.001 do
	game.Workspace.Door.CFrame = game.Workspace.Door.CFrame * CFrame.new(Vector3.new(0,-0.1,0))
	end

So everything works until the door should go back, it just teleports back to the first position without any animation. Does anyone know why this happens?

Thanks for the help, Xsodar