See error from console:
WebSocket connection to 'ws://localhost:8090/vaadinServlet/PUSH?v-uiId=0&v-csrfToken=27328352-6365-44a4-b980-1ca2d7a5bc1c&X-Atmosphere-tracking-id=0&X-Atmosphere-Framework=2.3.2.vaadin1-javascript&X-Atmosphere-Transport=websocket&X-Atmosphere-TrackMessageSize=true&Content-Type=application/json;%20charset=UTF-8&X-atmo-protocol=true' failed: Error during WebSocket handshake: Unexpected response code: 200
This is after upgrading to vaadin 8.0.0 Push annotation and manual enabling of Push do not seem to make a difference. It reverts to long polling.
My best guess is it is a version problem. You can see it mentions atmosphere 2.3.2 in the error, but vaadin-push 8.0.0 imports atmosphere 2.5.4