How to stop Fiddler displaying 407 and Tunnel To

How can I stop Fiddler displaying the "407" and "Tunnel To" which look to be generated twice before each successful "200"

GET https://i.sstatic.net/G1dzB.png 407 Proxy Authentication Required 
   ( Access is denied.  ) (text/html)
GET https://i.sstatic.net/G1dzB.png 407 Proxy Authentication Required 
   ( Access is denied.  ) (text/html)
GET https://i.sstatic.net/G1dzB.png 200 OK (image/png)

and

CONNECT http://www.gravatar.com:443 407 Proxy Authentication Required 
   ( Access is denied.  ) (text/html)
CONNECT http://www.gravatar.com:443 407 Proxy Authentication Required 
   ( Access is denied.  ) (text/html)
CONNECT http://www.gravatar.com:443 200 Connection established ()

I've enabled the Rule / Hide CONNECTs and the Filter / Show Only Intranet Hosts, but I still get these sessions

[Update] Tried the customize rules, OnBeforeRequest and added ...

if (oSession.HTTPMethodIs("CONNECT")) { 
    // works, the sessions are green
    // oSession["ui-color"] = "green"; 
    // doesn't work, the sessions appear in grey! 
    // oSession["ui-hide"] = "true"; 
}

Solution

Steve-- If you want to get a precise answer, save some traffic using File > Save > Session Archive Zip and share the SAZ file (or send using Help > Send Feedback) and I'll have a look.

HTTP/407s are shown because your client is behind an authenticating proxy server; each new connection results in an exchange of credentials to the proxy before the request is sent to the remote web server.

CONNECT requests are shown because when your client sends HTTPS requests, it first sends a CONNECT to Fiddler to tell it where to connect (because your client doesn't expect a proxy like Fiddler to be able to decrypt the secure traffic).

Using the Filters or ui-hide flag should work just fine; it's possible that it's not hiding for a few different reasons, including HTTP Errors or if Fiddler itself generated the requests (which might happen if you enabled Rules > Automatically Authenticate, for instance).

A SAZ file will show me exactly what's going on.