Hey @HF Designs 

Thank you for posting this question here in the community

If you're setting up a branded subdomain and using the NS (nameserver) method rather than the CNAME method, it sounds like you're trying to delegate the subdomain to another DNS provider or a different set of nameservers.

Here’s how you can approach fixing the "DNS record not found" issue:

1. Verify NS Records: Double-check that you have correctly set up the NS records for your subdomain at the parent domain's DNS settings. This typically means going to your domain registrar's DNS management section and adding NS records for your subdomain that point to the nameservers provided by your DNS provider.

2. Propagation Time: DNS changes can take time to propagate across the internet. Even after setting up NS records correctly, it might take up to 24-48 hours for these changes to fully propagate worldwide. During this time, tools like MXToolbox might report that the DNS records are not found because the changes haven't reached all DNS servers yet.

3. Check NS Configuration: Ensure that the NS records you've set are pointing to the correct nameservers. Any typo or incorrect nameserver configuration can lead to DNS resolution failures.

4. DNS Resolution Test: Use tools like dig (command-line tool) or online DNS lookup tools (such as mxtoolbox.com or dnschecker.org) to specifically check the NS records and the delegation of your subdomain. Verify that the nameservers listed match what you expect.

Let me know if this fixes it.

Thanks

Arpit