If you install version 8.8 stable there is an error in the installation which locks you out of the secure ports. For example you can manage WHM by going to
http://IP-address:2086, but you cannot access through SSL on port 2087 (
https://IP-address:2087).
This is caused by cPanel not creating a directory in the cPanel directory during the install. Here is how you can fix this:
The missing directory is:
/usr/local/cpanel/var/run/stunnel
Login to root via ssh and create the /var, /run and /stunnel directories.
You will then need to chown all directories to 'cpanel:cpanel'.
Then at the command line run the following command:
/usr/local/cpanel/startstunnel
This will fix the problem and you should be able to access WHM through the secure port.