NET::ERR_CERT_AUTHORITY_INVALID on custom domain despite active Let’s Encrypt certificate

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Hi Netlify Support,

My custom domains vintagestocklots.com and www.vintagestocklots.com are both returning NET::ERR_CERT_AUTHORITY_INVALID in Chrome.

The Netlify subdomain sprightly-concha-bb1700.netlify.app works correctly over HTTPS, so the deployed site itself is reachable.

I have already checked the following:

  • Netlify Domain Management shows HTTPS enabled.
  • Netlify shows an active Let’s Encrypt certificate covering both vintagestocklots.com and www.vintagestocklots.com.
  • I used “Renew certificate” today. Netlify now shows the certificate as updated today, but the browser error remains.
  • The apex DNS A record is 75.2.60.5.
  • www is a CNAME to sprightly-concha-bb1700.netlify.app.
  • There are no AAAA records.
  • There are no CAA records.
  • DNSSEC is disabled.
  • I tested on both Wi-Fi and 5G and receive the same certificate authority error.
  • I could not find an additional/inactive Netlify DNS zone for this domain.

Could someone from Netlify please check which certificate and certificate chain are actually being served for these custom domains, and whether the certificate needs to be repaired or reprovisioned on Netlify’s side?

I would prefer not to make further DNS changes because the domain also uses Microsoft 365 email and the DNS records for that service are working.

Thank you.