I am able to create a let's encrypt certificates for 18 domains and virtual aliases pointing to my WordPress Multisite. When I add 20 or more, the process seems to hang. No errors, just running. I can see the letsencrypt.cgi process running in top for 2 days now. Also, the last renewal was 0.54 months ago. So Let's Encrypt cert process is working just fine, but trying for 20 or more hangs.
Let's Encrypt limited amount of Domains