Character Parts Changing Size Upon Spawning

Hello, the issue I’m having is that I am making a sphere, parenting it to the character, but the sphere changes size.

The sphere used to always be (9,9,9) but when I changed the avatar proportions in the Game Settings, it has led to the sphere changing to (7.2,8.55,9) every time I try to spawn. There are no other running scripts that change part sizes, it was right after I changed character proportions that this began happening, but I really need to keep player proportions smaller. Thanks.

game.Players.PlayerAdded:Connect(function(player)
	player.CharacterAdded:Connect(function(char)
		local HRP = char:WaitForChild("HumanoidRootPart")
		local marble = Instance.new("Part")
			marble.BrickColor = BrickColor.new(11)
			marble.Transparency = 1
			marble.Name = "HitBox"
			marble.Position = HRP.Position
			marble.Shape = Enum.PartType.Ball
			marble.Parent = char
			marble.Material = Enum.Material.SmoothPlastic
			marble.CanCollide = false
			marble.Massless = true
		marble.Size = Vector3.new(9,9,9)
		print(marble.Size)
		marble.Locked = true
		local Hum = char:WaitForChild("Humanoid")
		local Weld = Instance.new("Weld")
			Weld.Parent = marble
			Weld.Part0 = HRP
		Weld.Part1 = marble
		local Velocity = Instance.new("LinearVelocity")
		local attachment = Instance.new("Attachment")
		attachment.Parent = HRP
		Velocity.RelativeTo = "World"
		Velocity.Attachment0 = attachment
		Velocity.Enabled = true
		Velocity.Parent = marble
		Velocity.MaxForce = 3000000
		print(marble.Size)
	end)
end)