When trying to log in using the top bar "Log in" module user gets CSRF error and is not logged in. Reproducible on tiki.org and dev.tiki.org. Not reproduced on doc.tiki.org. I feel it has something to do with the buggy cookie consent feature.
It does not happen when loggin in using the dev.tiki.org/login URL directly (instead of the top bar module).
You need to open new incognito window in Chrome/Firefox to "start fresh" and reproduce the issue.
Steps to reproduce in the attached screencast video.