Comment 4 for bug 1794844

Actually I wonder if the failure can be reproduced in French. Given the fail on the call to ipapi (US-based) and the fact that it doesn't fail all the time, I'm thinking perhaps a timeout error of some kind.

On the other hand, I'm told that importing urllib.request seems to produce different results than from urllib import request, so that may be part of the error. See here:
https://phab.lubuntu.me/D23
That should be able to be applied directly to /usr/lib/(i138-linux-gnu|x86_64-linux-gnu)/calamares/modules/automirror/main.py in a live system, then run the installer and see what happens.