First SSL in ea4_main.default NOT Default SSL Hostname Virtual Host
On examining the /var/cpanel/templates/apache2_4/ea4_main.default file in detail, I found the following defect:
httpd.conf first of all generates users vhosts SSL:
# BEGIN: HTTPS vhosts list
and only after that (almost at the end of the file):
# Default SSL Hostname Virtual Host
As result after generation via rebuildhttpdconf, we have user SSL as first (and default) SSL cert on WHM ip ( testing via curl -vk https://WHM_ip/ ). My suggestion:
Raise the "Default SSL Hostname Virtual Host" configuration section above "HTTPS vhosts list". It will make it possible to use default server SSL certificate as *default* SSL on WHM ip on HTTPS port.