LDAP connection not working.

[MSNRW]

I'm currently trying to get the LDAP connection working.
Unfortunatly I only get this error while trying to login to wiki.js.

If I change the IP or Port i get the message that the LDAP server couldn't accessed.
The LDAP Debug option is also switched on in the admin area, but no information are writtin into the log.

I'm running the wiki.js in a docker container, also the firewall of the docker host was switched off in order to test if that could be the root cause.

Do you have an idea how I can solve that issue or test more in detail to figure out what causing that problem.