timeout and login decline after attempting to create connection while on corporate proxy

Hello,

I have jsforce-ajax-proxy running in the background, but when I create a connection in my JSForce app as such:

var conn = new jsforce.Connection({
    loginUrl : 'https://test.salesforce.com',
    proxyUrl : 'http://localhost:3123/proxy/'
});

and do a login as such:

conn.login(user, (pass+token), function(err, userInfo) {
    console.log("DEBUG");
    if (err) {
        return console.error(err);
    }

I do not even get my console logging statement as it hangs. Eventually, after a LONG while, I get a timeout error:

POST http://localhost:3123/proxy?(some number here) net::ERR_EMPTY_RESPONSE
DEBUG
Error: Access Declined(…)

This does not happen at all when I am not under the proxy (and my app works fine), but I would like this to work behind a proxy. Is there a setting I can apply to do this, such as setting an http proxy variable? If it helps, I am behind something that looks like user:pass@proxy.company.com:port_id.

Start by reproducing conn.login with the shown proxyUrl through the corporate proxy, including its user:pass@host:port form, and inspect the jsforce-ajax-proxy request path. Done means the login completes behind the proxy without the timeout, ERR_EMPTY_RESPONSE, or Access Declined error.