In a bigsur Machine, we have a local proxy running and we are using manual system proxy settings (127.0.0.1 and port) to redirect the connections to the local proxy. The redirection is working fine for chrome, Firefox and majority of the apps. But Safari and few apps connections are not being redirected to the local proxy, and in safari for any website access we straight away see cannot find server error.
But if the proxy settings are added in a local pac file
function FindProxyForURL(url, host) {
return "PROXY 127.0.0.1:<port number>";
} and use this pac file Automatic Proxy configuration URL, (instead of manual settings)then everything works fine, including Safari and other apps.