Warning - errors were found in this domain's DNS records : NS record ns1.dnsmonkey.rocks. cannot be resolved to an IP address

Yes, another one :)

I've googled first and found several threads already but either they were answered real techie or there was no solution.

When I checked the DNS records of a domain I added it gives the error from the title and I don't know why.

DNS lookup and GTmetrix can't find my nameserver but maybe that's because I changed them from the old one to the new one.

Everything works fine, the site is online, FTP is working etc but just wondering why it's giving that error.

Also had some installation issues when I added server.dnsmonkey.rocks and the ns1 and ns2 said it didn't exist but read in an other thread to just skip the test. When I did that, twice it disconnected and could be resolved but after the second install I just restarted Virtualmin through the terminal and that seemed to work.

Also, i can only log through IP:10000 and not server.dnsmonkey.rocks.

Some assistance would be appreciated.

Thanks