Hi, @shiryam, this is happening because the Netlify DNS name servers were added as DNS records instead of changing the authoritative name servers to the Netlify DNS name servers. (The existing NS records should have been replaced instead of adding new records.)
The following instructions should assist with making the change:
Note, you don’t have to enable Netlify DNS to use a custom domain with a site. You can also use the external DNS instructions if you prefer.
Please let us know if there are any other questions about this.