If you try to make an Apache request for a server with an https port other than 443 (the default port), then the pinning mechanism stops working and as a result, when you swap a certificate, you can overhear https traffic using, for example, Burp (https://portswigger.net/Burp/help/proxy_using.html)
If you try to make an Apache request for a server with an https port other than 443 (the default port), then the pinning mechanism stops working and as a result, when you swap a certificate, you can overhear https traffic using, for example, Burp (https://portswigger.net/Burp/help/proxy_using.html)