I did some troubleshooting and figured out that when the update happened ISPConfig created a new virual host using port 8080 of the exact location I was using for port 80, which somehow conflicted, so I had to delete my custom port 80. given that, How can I make this work for me:
ProxyPass / https://privateip:8080/
ProxyPassReverse / https://privateip:8080/
Whenever I try to use port 443 on my webserver to forward proxy, the apache server gets an error:
Failed to start apache :
* Starting web server apache2
(98)Address already in use: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
Initially I had the control panel running on port 80. and it worked so I left it alone.