I used to use mqtt with mosquitto. Now i want to switch. The bare mqtt works with hiveMQ (hivemq-ce-2020.2), the web sockets unfortunately not. From the config.xml:
With the test script publish-socks.py  I don’t get a connect while it works with the old mosquitto server:
paho.mqtt.client.WebsocketConnectionError: WebSocket handshake error
But with curl I get an understandable error message from hiveMQ:
$ curl 188.8.131.52:9001
not a WebSocket handshake request: missing upgrade
What am I doing wrong? Grateful for hints.