SFR Core Code Help

We are testing with an SFR example and have found that removing the ‘id’ from the geometry prevents normal calculations, while retaining ‘id’ allows for normal calculations. We would like to inquire about the issue encountered.The code we are using is from

Jupyter Notebook Viewer.

When the original code removes the IDs for surfaces, cells, universes, and lattices, it can no longer perform the correct calculations.

We can’t be sure what happened. Does OpenMC not automatically assign IDs during calculations?
We hope that the official team can test the example mentioned above and identify the root cause of the issue. Thank you very much.