Websocket disconnects


I am trying to establish a WebSocket connection to a target URL provided by "eu4pro.loriot.io". When testing the connection on websocket(dot)org, everything seems to work.
In Node-Red, however, only some messages arrive before disconnecting...
On a different account (eu1.loriot.io), I generated another WebSocket URL (basically the same way). This somehow works without issues. I would be really grateful for any tips on how to find out why this is happening.

My node-red is installed on a VPS:
npm -v 6.11.3
node -v v10.17.0
node-red 1.0.2

Is there a way to log the WebSocket node to find out why it is disconnected?

Best regards