I have the same problem but none of the solutions works
my user in DB is configured as this
select * from ost_user_account;
+----+---------+--------+---------------+------+----------+--------+------------------+-----------------------+---------------------+
| id | user_id | status | timezone | lang | username | passwd | backend | extra | registered |
+----+---------+--------+---------------+------+----------+--------+------------------+-----------------------+---------------------+
| 5 | 6 | 9 | Europe/Berlin | NULL | NULL | NULL | ldap.client.p4i3 | {"browser_lang":"it"} | 2023-10-29 00:30:41 |
+----+---------+--------+---------------+------+----------+--------+------------------+-----------------------+---------------------+
the same user was able to login as Agent but not as client