Collision Group Help

I am trying to setup spheres that don’t collide with each other but they do collide with the map. I tried the following code, and it does not work. I am just now learning about collision groups. I used a player collision group script for this which does work, so I am not sure where I went wrong.

local ballCollisionGroupName = "Balls"
PhysicsService:CreateCollisionGroup(ballCollisionGroupName)
PhysicsService:CollisionGroupSetCollidable(ballCollisionGroupName, ballCollisionGroupName, false)

workspace.ChildAdded:Connect(function(Part)
	if Part:IsA("Part") and Part.Shape == Enum.PartType.Ball then
		PhysicsService:SetPartCollisionGroup(Part, ballCollisionGroupName)
	end
end)

I didn’t account for the part type being changed, adding a wait before checking if it is a part and checking the part type.