That's an IIS error, doesn't know how or can't route the request. Double check the port bindings - http to 81, https to 447 and the cert for 447 is the same as the one for 443. Next, either disable the firewall or add custom rules for opening the non-standard ports. For testing, I would turn off the firewall get it working then turn back on and add custom rules later.
Was still curious why you choose non-standard ports and it's a lot of extra work not just to set up, but for clients to use and remember. The only reason I could think is that maybe you're trying to hide the ports? Even then they could be discovered with a simple port scan.
IIS can handle multiple requests for different web adaptors on the same standard ports (80/443).