"Provision certificate" returns: "certificate parameter is required when updating an existing certificate."

Site name: ummahbrief-guide
Custom domain: guide.ummahbrief.com
DNS verification is successful, Let’s Debug shows all OK, but clicking “Provision certificate” returns: “certificate parameter is required when updating an existing certificate.”
Could you please clear/reset the stale certificate record for this domain so I can provision a fresh Let’s Encrypt certificate?