The dreaded "A DNS zone for this domain already exists on NS1" from Namesilo

I read the old posts. I’ve removed the DNS entries on Namesilo’s side.

Netlify site name: fluffy-gingersnap-c0d71d

The custom domain: flmedi.com
Tell us the error message: "A DNS zone for this domain already exists on NS1"

Unlike Name.com, there is no Delete DNS Zone or Delete All option on Namesilo and it will not allow blank nameserver entries. So I removed the DNS entries and edited the nameservers to use Netlify’s (dns1.p01.nsone.net).

Can I use Netlify’s DNS and SSL or am I stuck with Namesilo until I transfer it out? I have a second domain at Namesilo I wanted to use with Netlify, so the resolution here will inform me of next steps for that one. I won’t buy domains there in the future.