observe not registering reactive value

Hi,

Welcome to the RStudio community!

Reactive expression are only evaluated when they are needed. It is hard to guess from just this piece of code, but one thing that is a bit weird is you seem to be updating plots (output$plot_age, output$plot_age_zoomed) without using a renderPlot() function.

The observe is not the best reactive wrapper in this case, you would want to either make a reactive variable or put code in the render plot function.

library(shiny)

ui <- fluidPage(
  
  actionButton('myButton', "click"),
  plotOutput("plot1"),
  plotOutput("plot2")
  
)

server <- function(input, output) {
  
  dataPlot1 = reactive({
    input$myButton
    plot(data.frame(x = 1:5, y = runif(5)))
  })
  
  output$plot1 = renderPlot({
    dataPlot1()
  })
  
  output$plot2 = renderPlot({
    input$myButton
    plot(data.frame(x = 1:5, y = runif(5)))
  })
  
}

shinyApp(ui, server)

Please provide a reprex if this is not what you are looking for. Shiny debugging and reprex guide

Hope this helps,
PJ