DNS Domain Join Error

Hi, im trying to join a Mint 19 Client to my domain. I cleared DNS Entries as instructed in the error message;
but running the domain-join cli command still leads to this error:
Any idea why this is still not working?

Hi peterge,
i successfully did a domain-join with Ubuntu 18.04 last week, as described on https://github.com/univention/univention-domain-join
Mint 19 is also listed as supported distro, so i guess the setup should be straight forward as it is with Ubuntu.
Can you please post how you cleaned your DNS-Entries and what domain-join-cli.log says?