Hi Owen, I'm Ramesh, here to answer your query at the Microsoft Community.
This happens because Microsoft blocks some IP ranges from accessing its servers. As a workaround, you can use the Media Creation Tool to download the ISO.
Download Windows 11 Media Creation Tool (MCT) from this link:
https://go.microsoft.com/fwlink/?linkid=2156295
Run MCT and download the Windows 11 (24H2) ISO.
If that doesn't help, let me know so I can generate a direct download link and share the link here. Mention which language you need.