Hi using odoo 11

Authentication to ldap using TLS fails however it works when not using TLS. . Our setup is correct and we where able to verify by using  by the `-ZZ` flag in the `ldapsearch` command

Following is in the logs:

ERROR XXXX odoo.addons.auth_ldap.models.res_company_ldap: An LDAP exception occurred: {'desc': 'Connect error', 'info': '(unknown error code)'}

Any ideas, what the problem might be