Trigger event without changing reactive

[BetulaNana]

Related to my previous question, I wonder now how I can trigger an event without change of the reactive sh() here

openxlsx::read.xlsx(isolate(datafile()$datapath[1]), sh())

For example I upload an excel file with sheet name "table 1". Now, I upload another excel as replacement, but it's first sheet name is also "table 1". It won't trigger an event.
Here is the full code:

# EXCEL FILE SELECTION MODULE UI ------------------------------------------------------------
.input.xlsxUI <- function(id) {
  fileInput(inputId = NS(id, "file"), label = "Test-Upload (.xlsx format)")
}
# EXCEL FILE SELECTION MODULE SERVER ------------------------------------------------------------
.input.xlsxServer = function(id) {
  moduleServer(id, function(input, output, session) {
    # The selected file, if any
    reactive({
      # If no file is selected, don't do anything
      req(input$file)
      input$file
    })
  })
}
# SHEET SELECTION MODULE UI ------------------------------------------------------------
.input.sheetUI = function(id) {
  selectInput(NS(id, "sheet"), choices = NULL, label = "Sheet")
}
# SHEET SELECTION MODULE SERVER ------------------------------------------------------------
.input.sheetServer = function(id, datafile) {
  stopifnot(is.reactive(datafile))
  
  moduleServer(id, function(input, output, session) {
    #excel-file is uploaded --> update selectInput of available sheets
    observeEvent(datafile(), {
      choices_list = openxlsx::getSheetNames(datafile()$datapath[1])
      updateSelectInput(session = session,
                        inputId = "sheet",
                        choices = choices_list)
    })
    reactive(input$sheet)
  })
}
# UPLOAD MODULE UI --------------------------------------------------------
.ExcelUI = function(id) {
  tagList(.input.xlsxUI(id = NS(id, "xlsxfile")), # upload input
          .input.sheetUI(id = NS(id, "sheet")), # sheet select
  )  
}
# UPLOAD MODULE SERVER ------------------------------------------------------------
.ExcelServer <- function(id) {
  moduleServer(id, function(input, output, session) {
    datafile <- .input.xlsxServer("xlsxfile")
    sh <- .input.sheetServer("sheet", datafile)
    # when sheet is selected, upload Excel
    t = reactive({
      req(sh())
      openxlsx::read.xlsx(isolate(datafile()$datapath[1]), sh())
    })
  })
}
library(shiny)
library(shinyjs)
ui <- fluidPage(useShinyjs(),
                wellPanel(.ExcelUI( "upld")),
                wellPanel(verbatimTextOutput("out")))
server <- function(input, output, session) {
  xlsxfile = .ExcelServer("upld")
  output$out <- renderPrint(xlsxfile(), width = 40)
}
shinyApp(ui, server)