Check the manufacturer's instructions and avoid treating the cabinet as a general heavy storage surface. Movement during operation can make unsecured objects fall or create misleading noises.
Understanding this situation
A rattling bottle on top is a different issue from internal scraping, but a heavy object should not be used to suppress vibration. Stacking another appliance requires the correct approved arrangement, not simply placing it on the washer.
A useful next step
Keep the surrounding area clear and stable. If unusual movement occurs, stop use and investigate appropriately instead of adding weight. Tell the engineer about existing shelving or stacked equipment that affects access to the machine.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.