Deleted subdomain still stuck in domain (from site)

My Domain (kat-zentrale.de and www.kat-zentrale.de) are still bound to a site, but i removed them from that site. I can still see them in the domain overview. Those are very important, relevant server functions of the server behind the domain are not working anymore because it catches everything, but all domains just return 404. So how can I remove those (Sub-)Domains from the page? I already deleted the whole site, but i cant remove the domain bindings, its says it would be a system record.
Thanks in Advance

I investigated at WHOIS:

      Domain: kat-zentrale.de
      Nserver: dns1.p03.nsone.net
      Nserver: dns2.p03.nsone.net
      Nserver: dns3.p03.nsone.net
      Nserver: dns4.p03.nsone.net
      Status: connect
      Changed: 2020-03-04T02:05:39+01:00

Since kat-zentrale.de seems to use NS1,
please delete the record and domain there.

This is a topic outside of Netlify, so you should not ask for details here.

Balloon seems to be correct; it appears that you still have DNS entries with your registrar that point to Netlify for DNS for your domain. You need to change the entries with your registrar and, after those changes propagate, your domain will point elsewhere.

No, it is a netlify bug. I added the site to a netlify site and then deleted again but its stuck in netlifys domain overview.
I needed to delete the whole DNS Zone and recreate every single entry there.

hi Niwla, sorry to hear you have been had some trouble. Is the issue fixed now?

Yes, but maybe you could look into that bug, its annoying

great, glad to hear things are working, and, will do!