The Nameservers are not configured correctly for your .DE name(s), that is why we are failing to publish them. To test if a Nameserver is configured correctly for your .DE name you can use this tool: https://nast.denic.de/
You can find the test results for this case here: https://nast.denic.de/result/XX.de?ns1=bernie.dnspod.net&ns2=oleander.dnspod.net
Please note that the IP addresses of each Nameserver should differ by at least one number in any octet and at least one of them must be connected via IPv4. A zone file for your domain name should also be created on the DNS service provider's side in advance.
We recommend to contact the DNS service provider with these results for help. In the meantime, please use our default Nameservers to connect your domain name:
NS1.DNSOWL.COM
NS2.DNSOWL.COM
NS3.DNSOWL.COM
If anything isn't clear or if you need help with anything else please do not hesitate to contact us.