setProxy in JS HttpRequest no longer working?

[MichaelR]

Hi all,

after ugprading from 6.2.7 (on CentOS 8) to 6.4 (on Rocky Linux 9), notifications to RocketChat are no longer working for me. I have to go through an HTTP proxy, but it seems the call to setProxy is simply ignored.

I'm using the default script for RC, which has

if (typeof RocketChat.HTTPProxy !== 'undefined' && RocketChat.HTTPProxy !== '') {
request.setProxy(RocketChat.HTTPProxy);
}​

I made sure that HTTPProxy is set via debug messages, and even hardcoded request.setProxy("http://myproxyIP: port") without any if()-conditions around the call. But whatever I try, the request always fails with "Sending failed: Error: cannot get URL: Couldn't connect to server.".
When I run tcpdump, i cannot even see an outgoing TCP connection to the proxy.

As I said, the very same script in 6.2.7 worked just fine.

Any ideas, what else I could try?

Cheers,
Michael

[MichaelR]

(As expected) no change with 6.4.1.

In the meantime, I tried using IP addresses instead of hostnames everywhere (proxy URL, server name). Also different prefixes (http://, https://, none) for the proxy.