Hi Vlad,
One of the ways in which we determine the HTTP port for a service is to send a HEAD request and wait for a response. It appears that the service in question is responding to HEAD requests in about 2.5 seconds. This is longer than our current threshold and hence the test request times out.
You can get around this issue by setting the PORT env var to the port number you’d like to listen on.( 3000 in this case)