Nginx websocket timeout for Vaadin 23.1.7 startup in dev mode

I have a Vaadin 23.1.7 Starter spring boot app behind a nginx proxy that times out every 60 seconds in development mode. In production mode the timeout does not occur.

My nginx config is the same for both environments and contains:

location / {
    proxy_pass              http://192.168.2.10:17080/;

    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $host:$server_port;

    proxy_cookie_path ~*^/.* /;
    proxy_redirect off;

    # support websockets
    proxy_set_header        Upgrade $http_upgrade;
    proxy_set_header        Connection "Upgrade";
    # Default vaadin heartbeat is 300s, so miss two heartbeats and then close websocket
    proxy_read_timeout      630;
    proxy_connect_timeout   630;
    proxy_send_timeout      630;
}

I assume vaadin dev mode has some kind of control websocket to manage the hotloading of dev resources but this websocket somehow falls outside the scope of the defined nginx location.

Can anyone please help with a working nginx config please.

Franz