Replying to my own comment to update on the issue: The issue seems to be related to session-id and CSRF token not being correct. Unfortunately, I would need to try a clean install (I probably messed with some Django settings) and test again which I can't do right now due to other work that I have. So, for now, I've just disabled fr locale totally - meaning, you will only see the website in English. Since you mentioned that the translation is bad, I'm not sure how helpful it will be to just leave a bad translation as default. Sorry about this!