Maybe i'm missing something, and would appreciate clarification.

Perhaps psutil is wrong, but it gives an answer that has something to do with the actual situation.

On platform 2, i have 2 Intel Xeon Gold 6138, each with 20 physical processors, 40 logicals.

you are saying i need to rely on os.cpu_count(), which outputs '128'. Can you elaborate on this?

Moreover, when attempting to parallelize on the processors, i reach 25% utilization, which suggests Python 'sees' only one processor group.