How may I observe expected physical interactions while using Rigidbody.MoveRotation()?

Greetings Developers!

I have a circular platform (built using a sphere with scale 10, -0.1, 10) of which I control the pitch (x) and roll (z) to balance a sphere on top of it.

@Eno-Khaon kindly provided the code below to make the platform move as I desire: limited rotation on both the x and z axes (frozen y axis), so that the platform cannot go beyond a discretionary tilt angle in any direction. Their suggestion is an improvement to my transform.localRotation approach (Click here to visit my previous question).

One challenge I intend to add to the 'game' are heavy, falling objects meant to destabilize the platform while balancing the ball. So, I created a HeavyCube (50 mass) and let it drop from a certain height. The issue is that with Rigidbody.MoveRotation(), the cube simply goes through the platform, and I just cannot understand why. My guess is that: between providing discrete rotations through Rigidbody.MoveRotation() and honoring physical interactions between the platform and the cube, the engine gives precedence to the former, causing this abrupt 'fall-through-collider' effect (fyi, the effect happens regardless of whether I am holding down any input key or not).

Oppositely, the collision works as I would expect when using the transform.localRotation approach (i.e. what I mean by 'expected physical interactions').

Question: How may I observe expected physical interactions while using Rigidbody.MoveRotation()?

Unsuccessful attempts at making this work:

1. changing the mass of the cube (keeps happening even with mass 1);

2. Making the platform kinematic and having the cube apply downward force (gave up as way too advanced for me at the moment);

3. Introducing if-statements to apply Rigidbody.MoveRotation() only when collision with HeavyCube is not detected (closest I got to something acceptable, but still ugly and non-realistic).

Would also deeply appreciate an explanation as to what is causing the fall-through-collider effect.

Thanks in advance, and please let me know if I can provide any additional info to make the question clearer. Cheers!

 public class TiltPlatform : MonoBehaviour
     {
         public float maxAngle; // The maximum angle of rotation allowed
         public float tiltSpeed; // Rotation speed, up to maxAngle
         public float returnSpeed; // Speed to return to original orientation
         Vector2 currentInput; // The current frame's input to apply to the total
         Vector2 totalInput; // The combined totals from rotation inputs
         private Rigidbody m_Rigidbody;
     
         private void Start()
         {
             m_Rigidbody = GetComponent<Rigidbody>();
         }
     
         // Update is called once per frame
         void Update()
         {
             currentInput = new Vector2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical"));
         }
     
         private void FixedUpdate()
         {
             // If no input is being provided, ease total input(s) toward 0
             if (Mathf.Approximately(currentInput.sqrMagnitude, 0.0f))
             {
                 // Time.deltaTime is implicitly converted to Time.fixedDeltaTime
                 // when called inside FixedUpdate()
                 totalInput = Vector2.MoveTowards(totalInput, Vector2.zero, returnSpeed * Time.deltaTime);
             }
             else
             {
                 // If there's input, apply it to the running total here
                 totalInput += currentInput * Time.deltaTime * tiltSpeed;
                 // If the total vector length exceeds the maximum, adjust it
                 if (totalInput.sqrMagnitude > maxAngle * maxAngle)
                 {
                     totalInput = totalInput.normalized * maxAngle;
                 }
                 // Note that this approach should move smoothly toward the current
                 // input, while not aligning to cardinal directions easily. 
                 // There are many ways to design this, so this is simply
                 // one of many options available
             }
             // Now, regardless of how the totalInput has changed, the rotation can be
             // set at this point (add restrictions as desired)
     
             m_Rigidbody.MoveRotation(Quaternion.AngleAxis(totalInput.x, Vector3.forward) * Quaternion.AngleAxis(totalInput.y, Vector3.left));
         }
     }