ggvis linked brushing bug

app

library(shiny)
library(ggvis)

shinyApp(
  ui =bootstrapPage(
    actionButton("randomize", "Randomize"),  
    ggvisOutput("plot1"),
    ggvisOutput("plot2"),
    verbatimTextOutput("summary")
  ),

  server=function(input, output, session) {
    
    main.data<-cocaine # staring data
    
    get_data<-reactive({
      input$randomize # need this for data update
      cocaine <- main.data[sample(1:nrow(main.data),20), ] 
      cocaine$id <- seq_len(nrow(cocaine))
      return(cocaine)
    })
    
  
  observe({   
    #new data
    cocaine <- get_data()
  
    lb <- linked_brush(keys = cocaine$id, "red") # does not reset after data update?
    
    cocaine %>% 
      ggvis(~weight, ~price, key := ~id) %>%
      layer_points(fill := lb$fill, fill.brush := "red", opacity := 0.3) %>%
      lb$input() %>%
      set_options(width = 300, height = 300) %>%
      bind_shiny("plot1") # Very important!
    
    # A subset of cocaine, of only the selected points
      selected <- lb$selected  

    cocaine_selected <- reactive({
      input$randomize
      cocaine[selected(), ]
    })
    
    cocaine %>%
      ggvis(~potency) %>%  
      layer_histograms(width = 5, boundary = 0) %>%
      add_data(cocaine_selected) %>%
      layer_histograms(width = 5, boundary = 0, fill := "#dd3333") %>%
      set_options(width = 300, height = 300) %>%
      bind_shiny("plot2")
  
      #summary of selected (Selected does not react)
      output$summary<-renderPrint({
        matrix(selected())
      })
    })
  }
)