Issue with adding domain: A DNS zone already exists on NS1

I have a issue with adding domains to Netlify DNS.

Domain names are: barterhaber.com and balhaber.com

When I’m trying to add these domains to Netlify DNS it gives A DNS zone for this domain already exists on NS1, the DNS provider backing Netlify DNS
Please contact NS1 with the domain name for support.

I’ve already added other domain names from same domain registrar and I got no error.
I added these domains successfully then due to some reason deleted them. After that I tried to add again but I confront with this error.
I also submitted the issue to ns1 but I don’t think that is the problem.

I will appreciate if you could help.

Thanks,

Hi there, thanks for reaching out! I confirmed that these DNS zones are not located in Netlify. You’ll need to look into where this domain has been hosted in the past – for example, it could be somewhere like Squarespace. Unfortunately, we don’t have much insight into this and NS1 does not divulge this information to us!

It used to hosted on https://www.alastyr.com/ and its was a WordPress website. Do you think this cause that problem?

Possibly. But in this case we’d encourage you to reach out to NS1 for support on this. Usually there are still DNS zones in their ‘parking lot’