Python in Excel is enabled but the runtime never downloaded

This issue occurs on multiple devices in my Microsoft 365 Family subscription, across different networks (including mobile hotspot). Python UI is enabled on all devices, but the runtime never downloads on any of them.

VBA HTTP requests, WEBSERVICE(), and Power Query also fail with the same 400/blank response pattern, which indicates the Excel networking sandbox was never initialized. This aligns with the ghost‑runtime state described by the engineering team.