Port 8080 can't retrieve issuer certificate!

Hi,
I have a GeoTrust QuickSSL Premium Wildcard certificate
I can run the ssl on the hostname : wh1.pro-fhi.net
And work fine on the interface with port 8080
But, when checking ssl I have the error to install intermediate/chain cert
So I edited /etc/apache2/sites-available/ispconfig.vhost
Add line SSLCertificateChainFile /usr/local/ispconfig/interface/ssl/ispserver.bundle just after SSLCertificateFile and SSLCertificateKeyFile
Restated apache2 but not the issue.
In the bundle file there is the intermediate and root certificate.
I try with bundle file as SSLCACertificateFile
I try SSLCACertificateFile directly to load Intermediate file or/and root file
Whitout this certficiate work correctly I can't use WHMCS module ISPCONFIG given cURL error 60: SSL certificate problem: unable to get local issuer certificate when trying to testing server configuration of the whmcs module.

Thanks for help
Sebastien

 

Why?
ISPConfig manual explains how to install purchased certificate on page 210 (on my ISPConfig 3.1 Manual).
Testing your current certificate shows errors, tool says it is self signed. It used to be OK, the cached result was fully OK at https://www.sslshopper.com/ .
Easier way is to use Let's Encrypt certificate.
https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/