Hi @aversfeld
never delete active certificates if you don't have another certificate.
First, check your vHost, if the www subdomain is removed.
Then, what says
certbot certificates
You need the name of your current certificate.
Then try
certbot --cert-name nameOfYourCertificate -d conservationsymposium.com -d archive.conservationsymposium.com
The other parameters certbot should ask.
That overrides your existing certificate.