Let's Encrypt SSL certificate not renewing automatically 2nd time consecutively

Hi, folks. I need some help troubleshooting. For the second straight time, my Let’s Encrypt SSL certificate did not renew automatically. In reading the relevant threads here, I managed each time to renew the certificate by removing the old one and rebuilding the app. I was under the impression that doing this would cause the renewal to happen automatically next time. It did not.

I don’t see any evidence of a cron job running anywhere that tries to renew the certificate. I presume I ought to look in the various places on the host machine, as opposed to inside the Docker container. Do I have that right? crontab -l says “no crontab for root” and I see nothing in /etc/cron*.

As a result, I can’t feel confident whether my server is (1) not attempting to renew the certificate or (2) attempting and failing. Is someone willing to guide me through troubleshooting this?

Unfortunately, since I nuked shared/standalone/{letsencrypt,ssl} in order to provision the certificate anew, I don’t have old logs to look through. How would I at least verify that the cron job is installed so that I can check the logs the next time the system attempts to renew the certificate?

Thanks.