Websocket server message disconnects you from the world

[Maescool]

Running on Linux Ubuntu 22.04.4

Connecting from the client '/connect' function connects to the websocket server.
When the websocket server sends a message, it kicks you out of the world saying "Disconnected from server"
the websocket connection does stay open.
This happens both on a local and multiplayer.

The websocket server itself is ok, since this works correct when I try with my android phone or windows.