No, you have done everything right. At least from the point of view of DNS. That you can not use multiple nameservers is a limitation of Cloudflare (limit in th

No, you have done everything right. At least from the point of view of DNS. That you can not use multiple nameservers is a limitation of Cloudflare (limit in the sense of: Cloudflare can only offer their services in the Free and Pro plan if they have full control over all nameservers).