Hi, @Mertlin, and welcome to our Netlify community site.
I see that NS records were added for Netlify DNS in the DNS configuration at the existing DNS service. Note the source of the reply in the answer below:
mk-eggendorf.at. 7200 IN NS dns4.p04.nsone.net.
mk-eggendorf.at. 7200 IN NS dns3.p04.nsone.net.
mk-eggendorf.at. 7200 IN NS dns2.p04.nsone.net.
mk-eggendorf.at. 7200 IN NS dns1.p04.nsone.net.
;; Received 133 bytes from 126.96.36.199#53(ns.second-ns.com) in 179 ms
We are getting an answer that shows the name servers used by Netlify DNS but … the answer isn’t coming from those name servers, it is coming from
ns.second-ns.com. More information can be found in the WHOIS record for this domain (a portion of which is copied below):
registrar: Hetzner Online GmbH ( https://nic.at/registrar/225 )
registrant: <data not disclosed>
tech-c: <data not disclosed>
changed: 20191217 10:45:19
This shows that the name servers where never changed. Our NS records were created but they are not actually in use. To switch to Netlify DNS, please consult the documentation for the domain registrar to find out how to change (not add) the name server records there.
If there are other questions about this, please let us know.