Cannot login using LDAP

Closing this issue, I think I have located the issue elsewhere.

What was the problem ?
For me, it seemed to be caused by mail_login ( https://www.drupal.org/project/ldap/issues/3404104 💬 LDAP authentication is successful, but the LDAP-authenticated user cannot log in. Meanwhile, it can log in if flood attempts block the account. Closed: works as designed ), but I need to dig all possibilities.