Hy Thyran, i solved this problem: Wordpress installation on Nethserver (multiple vhosts) - #135 by michelandre
the easier way seems to be: Improved Certificate Management - #10 by danb35
I am also unable to navigate to my nethserver gui environment using FQDN i have to use the local ip and ports
Have you checked System → Hostname/Alias?
in my case works well:
Hostname FQDN: srv01.mydomain01.tld
Alias: mydomain01.tld, mydomain02.tld, sub.mydomain02.tld
I can address my Nethserver UI using https://mydomain01.tld:9090 or https://srv01.mydomain01.tld:9090
Best regards, Marko