Why Does this Part Rotate Oddly?

I am using CFrame and Vector 3 to create a Sliding Door made of Unions.

Here's the Hierarchy.

This is the door before the door opens.

Then this happens as it's moving.

And it just stays like that.

This is the script:

local Door1 = script.Parent.Parent.Door1
local Door2 = script.Parent.Parent.Door2
local State = script.Parent.Parent.State

script.Parent.ClickDetector.MouseClick:connect(function()
    if State.Value == 0 then
        State.Value = 1
        for i = 1, 30 do
            Door1.CFrame = CFrame.new(Door1.Position + Vector3.new(.1, 0, 0))
            Door2.CFrame = CFrame.new(Door2.Position - Vector3.new(.1, 0, 0))
            wait()
        end 
        wait(2)
        for i = 1, 30 do
            Door1.CFrame = CFrame.new(Door1.Position - Vector3.new(.1, 0, 0))
            Door2.CFrame = CFrame.new(Door2.Position + Vector3.new(.1, 0, 0))
            wait()
        end
        State.Value = 0
    end
end)

If you could give me an explanation as to why it rotates that way, it'd be much appreciated. Thanks!