I've just added my domain, enabled letsencrypt and then added a subdomain. It also does't work when removing and re-enable letsencrypt after I've added a subdomain. You can see the errors I get within the letsencrypt.log. I don't know how to solve this by myself. I've done all the DNS checks and so far everything seems perfectly fine.
Sorry it took me so long, but I setup a new test server and setup the DNS to resolve for a test domain (technically a subdomain) provided by
https://dynamix.run. After adding my domain to the panel, I enabled Let's Encrypt. That worked fine. I then created a sub-domain on the sub-domain. Upon loading the sub-domain, it too was now encrypted with a valid Let's Encrypt SSL Certificate. If your DNS isn't resolving properly / the subdomain doesn't resolve to the same server IP that is making the request for the certificate, it will not work. Usually, any errors are clearly written to the Let's Encrypt log file. Please attach your Let's Encrypt log file that contains the errors.
It appears the panel is working properly / intended from the dedicated testing of this scenario I performed tonight... as long as everything is configured properly, of course.
