Forgot to flush

web/server.go

@@ -174,9 +174,10 @@ func (s *Server) HandlerAttemptStream(w http.ResponseWriter, r *http.Request) {
 		case <-r.Context().Done():
 			return
 		case <-ticker.C:
-			if _, err := io.WriteString(w, ": %s\n\n"); err != nil {
+			if _, err := io.WriteString(w, ": keep-alive\n\n"); err != nil {
 				s.ServerLogger.Warnw("Error writing event", "error", err)
 			}
+			flusher.Flush()
 		}
 	}
 }