SSL is not enabled in Nginx configuration for (sub)domains with alias domain
Website domain = **domain.tld ** or sub.domain.tld + alias domain = domain.tld > SSL is not activated in Nginx configuration
Website domain = domain.tld or sub.domain.tld + alias domain = sub.domain.tld > SSL is correctly activated in Nginx configuration
So the "listen *:443 ssl" is not added to the Nginx configuration when the alias domain is a 'parent' domain.