I get similar error too.
[webpack-dev-server] [HPM] Error occurred while proxying request localhost:8081/api/v2/status to http://127.0.0.1:4943/api/v2/status? [ECONNREFUSED] (https://nodejs.org/api/errors.html#errors_common_system_errors)
I even get something similar when i try to test http outcalls functions locally.