no login possible with firefox esr 52.9

Summary

Logging in with firefox esr 52.9.0 is impossible via the login boxes on the frontpage and via /login on both the normal site and beta.foo..

Steps to reproduce

Put your credentials in and hit enter.

What is the current bug behavior?

The page seems to be reloading and does not put out any error message,if you are on the front page. On the /login page you get redirected to the front page.

What is the expected correct behavior?

a successful login