Best way to have 3D balls bouncing in a physical container?

Godot Version

4.3.stable

Question

I have a sphere cage that must contain a bunch of balls that bounce around as the cage spins. The sphere cage is a hollow sphere with a CollisionShape3D created from the MeshInstance3D of the cage. Inside the cage I am spawning one small ball that is a RigidBody3D which has a sphere CollisionShape3D attached to it. However, when I run the game, the small sphere disappears (likely due to obscure collisions). Is there a better way to tackle this?