"Unable to connect to localhost on port 1702, error: Connect error: No error" when trying to connect to localhost:1702 and other IP addresses NO MATTER WHAT

[ProjectHSI]

Exact URL: ws://localhost:1702/commands_editor

Of note: This specific port will work when connecting via the browser (about:blank, "new Websocket("ws://localhost:1702/[etc]"). The server is running and can be connected to (signified by the intended client running fine and the browser connecting and "working" just fine).

Of additional note: I can't change the server code, but the server doesn't seem to be related here, since the message shows up even if the server isn't running.

The server does not use TLS.

occurs in both the WS example application and in my own app.