Gradle sync failed: Connection refused

Question

So I just installed Android Studio again after a long time and it asked me to configure the proxy, so I did. I tested the connection and it worked.

Then it asked me

Answer 1

I find when I change the option of Preferences -> Appearance & Behavior -> System Settings -> HTTP Proxy to Manual proxy configuration， the gradle properties of the project won't change, so I add:

systemProp.http.proxyHost= myProxyHost
systemProp.http.proxyPort= myProxyPort

Then it runs well.