Tweening a characters "Right Arm" position does not seem to work?

Hello, I am having a really bothersome issue that I cannot seem to find the solution too. I have a script that fires a remote event and another script that receives the event and tweens the characters' arm's size. The tweening of the arm's size seems to work, but it tweens in both directions. For example: https://gyazo.com/6386af0c8f8352242207ecb8d5424ae9 I wanted to only tween in front so I tried changing the position in the server script, but it does not seem to work. Even if I try to change the position manually (going through the explorer, character, right arm, position, etc.), it still does not change. I am confused on why.

Here is my server script:

local tweenService = game:GetService("TweenService")

local replicatedStorage = game:GetService("ReplicatedStorage")
local pistolEvent = replicatedStorage:FindFirstChild("GumPistolEvent")


pistolEvent.OnServerEvent:Connect(function(player)
    local character = player.Character or player.CharacterAdded:Wait()
    local rightArm = character:WaitForChild("Right Arm")

    local tweenInfo = TweenInfo.new(0.5, Enum.EasingStyle.Linear, Enum.EasingDirection.Out, 0, true, 1)
    local armProperties = {Size = Vector3.new(rightArm.Size.X, rightArm.Size.Y * 5, rightArm.Size.Z), Position = Vector3.new(10,10,10)}
    local armTween = tweenService:Create(rightArm, tweenInfo, armProperties)

    armTween:Play()

end)