How to attach a dropdown list to a cell in rhandsontable

Question

I have a rhandsontable with two columns named Method and Capitalization Order. I have tried to attach a dropdown list to the cell of the Capitalization Order conditioned by the value of the Method. However, I am getting the "Error: trying to select less than one element in get1index".

What is wrong with my script below? I would be grateful for any help.

df1 <- data.table(
  "Method" = as.character("Uniform", "Uniform"),
  "Capitalization Order" = NA_character_,
  stringsAsFactors = FALSE
)

ui <- dashboardPage(
  dashboardHeader(title = "FV CALCULATION"),
  dashboardSidebar(
    menuItem("Home", tabName = "home")
  ),

  dashboardBody(
    tabItems(
      tabItem(
        tabName = "home",
        column(
          "Fair Value Calculation",
          width = 12,
          rHandsontableOutput("TableV1"),
        )
      )
    )
  )
)

server <- function(input, output) {

  DF1 <- reactiveVal(data.frame(df1))
  
  observeEvent(input$TableV1, {
    DF1(hot_to_r(input$TableV1))
  })

  output$TableV1 <- renderRHandsontable({

    CapitalizationOrderOptions <- c(NA_character_, "monthly", "quarterly", "semi-annual", "annual")

    DF2 <- rhandsontable(DF1(), rowHeaders = NULL, stretchH = "all", selectCallback = TRUE, height = 300) %>%
      hot_col("Method", readOnly = TRUE) %>%
      hot_col("Capitalization Order", allowInvalid = FALSE, type = "dropdown", source = NA_character_, readOnly = TRUE)
    
    if (!is.null(input$TableV1_select$select$r)) {
      
      selectedMethod <- DF1()[input$TableV1_select$select$r, "Method"]
  
      if (selectedMethod == "Uniform") {
        DF2 <- DF2 |>
          hot_col(col = "Capitalization Order", allowInvalid = FALSE, type = "dropdown", source = CapitalizationOrderOptions) |>
          hot_cell(row = input$TableV1_select$select$r, col = "Capitalization Order", readOnly = FALSE) |>
          hot_table(contextMenu = FALSE)
      }
    }

    DF2

  })
}

shinyApp(ui = ui, server = server)