These Apache Proxy rules will send all traffic to the backend host

Which causes letencrypt to fail when trying to renew the SSL Cert on the Proxy Host because the request for http://yoursslcerthost.example.com/.well-known/  gets incorrectly passed to the backend host

So to make it work you need to tell mod_proxy to ignore that path as follows. Then you certbot-auto renew --no-self-upgrade command will complete successfully

The error you will see when running certbot-auto manually may look like