This means that your this DN doesn't exist.
Wordpress, at least from LDAP standpoint, is a pretty poor application that is, I suppose, building/forging DN before performing LDAP bind. I can't see any other solution than this otherwise it would never find DN like "=test,ou=Users,dc=jabber,dc=local".
If "uid" is missing, you can try a workaround by filling the "LDAP Login Attribute" field shown in your second picture with "uid".
Another evidence that Wordpress is poor: account suffix setting is stupid !
Not entering onto too much detail, LDAP aware application asks you to set baseDN, LDAP server, port, attribute used to login and perhaps filter. Based on this, DN should be retrieved from an anonymous LDAP search and never build or forged.
If there is no mistake in your settings, then try to have a look at Wordpress forum because it looks like a bug to me