Postman can't reach localhost
I was having similar issue with HTTP calls to local ASP.NET Core Web API apps. Changing the proxy settings didn't fix it for me.
Finally fixed it by turning off File > Settings > General > SSL Certificate Verification
Hope that helps someone out there.
I have the same issue. What works for me is:
Open File -> Settings -> Proxy
Then, enable proxy and put 127.0.0.1 : 80, if your web server runs on 80.
In the git thread, they say it is a known issue, so hopefully it will get resolved soon.
I solved this by Turning off System proxy of Postman.
Open File -> Settings -> Proxy
Then Turn off Use System Proxy