When I open Fiddler Classic, the Firewall rules no longer work. For example, I have a rule blocking all outbound traffic from Google Chrome. When Fiddler is not opened, the rule works and I am unable to access the internet through Chrome, but once I open Fiddler, the Firewall rule stops working and I can browse the internet normally.
I believe this has something to do with Fiddler connecting me to a proxy which bypasses the Firewall. So I tried unchecking “Act as system proxy on startup” under Options → Connections, but this causes Fiddler not to record any traffic at all. I also tried selecting “No Proxy” under the Gateway tab, but this does not seem to have any effect.
How can I fix this issue? Do I have to configure the Firewall settings to apply to the proxy? I am using Windows 10.