Yes, an item projecting below or across a rack can interfere with the intended movement. Check the model's loading guidance before starting.
Understanding this situation
A repetitive knock may come from a load obstruction, but do not assume every new noise has that cause. The machine should be stopped safely before any accessible check; reaching into an active wash is unsuitable.
A useful next step
Reposition the utensil in an approved location and ensure it cannot fall through. Do not remove a guard or spray arm to create space. Report continuing noise or poor cleaning after suitable loading rather than repeatedly running a noisy test.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.