Need to log-in twice

For the attention of [Maintenance triage meeting]: a client reported that they often have to log in twice. After trying once the page refreshes and then they are presented with the log-in screen again; after logging in again they successfully access the cms- but it takes 2 attempts.

cdekort also stated that she had experienced this and thinks it may have something to do with session expiry. E.g. it only happens if the user's session expires and they are logged out and then have to log-in again- but this is not certain and the problem could be unrelated to session expiry.

Needs investigation.