Shelly Plus H&T not connecting to websocket

Shelly Firmware 1.0.3
Homeassistant 2023.9.3

Hi,
I changed the shelly configuration according to the documentation to

Outbound websocket settings:

  • Enable Outbound Websocket
    Connection type: TLS no validation
    Server: ws://192.168.178.64:8123/api/shelly/ws

This is my local address for homeassistant. I have no SSL certificate installed and homeassistant is not reachable from the internet.
I added the Shelly smart home integration as well as the HACS ShellyForHass integration. My shelly H&T is recognized but without device nor entities.

Shelly does not connect to the websocket, what can be the reason why it is not working.
The websocket is enabled, but websocket is disconnected (shelly configuration webside on the top right).
The debug log contains:
"data": "shelly_http_client.:606 0x3ffdf160: Finished; bytes 240, code 404, redir 0/3, auth 0, status -19: Invalid WebSocket handshake response"

I do not know why the websocket handshake is invalid or what the problem is and I’m stuck on this.
Can you please help me to find the problem and get the websocket connection working?

Thanks!

I solved my issues.

I’ve installed the ShellyForHASS integration from HACS. After removing the Homeassistant integration of Shelly works which means that the Shelly could connect to the Websocket after rebooting.

The second issue was that my Shelly was recognized without device and entities. This seemed to be a bug in Homeassistant. After upgrade to 11.1 the device and entities were there!