Problem with `filter()` input `..1`. with shiny R

I'm trying to build a shiny app that filters a data frame based on user entries, however, i'm struggling using a function I created to do this task, the error Problem with 'filter()' input '..1'. x Input '..1' must be of size 9 or 1, not size 0. keeps apperaring. I found a similar issue here but the answer didn't help.

Here's my code. And also here are the xlsx and csv files with example data.

I appreciate a lot your help

library(shiny)
library(dplyr)
library(shinythemes)
library(shinydashboard)
library(shinyjs)

ui <- fluidPage(
  useShinyjs(),
  theme = shinytheme("flatly"),
  tabsetPanel(
    id = "tabs",
    tabPanel("Portafolio",
             sidebarLayout(
               sidebarPanel(
                 titlePanel("Seleccione las variables deseadas"),
                 uiOutput('fondo'),
                 uiOutput('reg'),
                 uiOutput('seguro'),
                 uiOutput('prod_sap'),
                 hr(),
                 actionButton("addbutton","Añadir")
               ),
               mainPanel(
                 titlePanel("Vista previa del portafolio"),
                 tableOutput('courseTable'),
                 actionButton(inputId = "continue", label = "Cotizar")
               )
             )
    ),
    tabPanel("Cotización",
             tableOutput('envio'))
  )
  )


server <- function(input, output, session) {
  fondo_edo <- reactive ({
    read.csv("E:/Input Fondo-Edo-Reg_example.csv") 
  })
  
  output$fondo <- renderUI({
    times <- input$addbutton
    fondos_todos <- as.vector(unique(fondo_edo()$FONDO))
    div(id= letters[(times %% length(letters)) + 1],
        selectInput("fondo_selec","Fondo:", choices=fondos_todos,selectize = T))    
  })
  
  fondo_edo1 <- reactive({
    subset(fondo_edo(), FONDO %in% input$fondo_selec)
  })
  
  output$reg <- renderUI({
    reg_todos <- as.vector( unique(fondo_edo1()$REGIÓN) )
    selectInput("reg_selec","Región:", choices=reg_todos, selectize = F)    
  })

  output$seguro <- renderUI({
    times <- input$addbutton
    div(id=letters[(times %% length(letters))+1],
        selectInput("seguro_selec","Seguro agricultura protegida:", choices=c("","Cosecha_Esp", "Inversión", "Planta"), selectize = F))    
  })
  
  output$prod_sap <- renderUI({
    times <- input$addbutton
    div(id=letters[(times %% length(letters))+1],
        conditionalPanel("input.seguro_selec == 'Inversión'",
                         selectInput("prod_sap_selec","Nombre producto SAP:", choices= "Tradicional")),
        conditionalPanel("input.seguro_selec != 'Inversión'",
                         selectInput("prod_sap_selec2","Nombre producto SAP:",choices = c("","Establecimiento", "Mantenimiento", "Producción"), selectize = F)))
  })

  values <- reactiveValues()
  values$df <- data.frame("Fondo" = numeric(0), "Región"= numeric(0), "Tipo de práctica"= numeric(0),
                          "Seguro agricultura protegida"= numeric(0))
  
  newEntry <- observe({
    if(input$addbutton > 0) {
      
      newLine <- isolate(c(input$fondo_selec, input$reg_selec,
                           "RIEGO", 
                           ifelse(input$seguro_selec=="Planta", paste0(input$seguro_selec,"/",input$prod_sap_selec2),
                                  input$seguro_selec)))
      isolate(values$df[nrow(values$df) + 1,] <-newLine)
    }
  })
  
  output$courseTable <- renderTable({values$df})
  
  observeEvent(input$continue, {
    updateTabsetPanel(session = session, inputId = "tabs", selected = "Cotización")
  })
  
  cotizacion <- reactive({
    isolate(busca_folios(fondo_edo(),values$df$Fondo, values$df$Región,
                         values$df$Seguro.agricultura.protegida))
  })
  output$envio <- renderTable({cotizacion()})
  
  # cotizacion <- reactiveValues()
  # cotizacion$df <-  busca_folios(fondo_edo(),values$df$Fondo, values$df$Región,
  #                                values$df$Sistema.de.producción, values$df$Seguro.agricultura.protegida)
  # 
  # output$envio <- renderTable({cotizacion$df})
}


runApp(shinyApp(ui,server))


#### Funciones ####

busca_folios <- function(tabla_fondos, fondo, reg, cultivo, seguro){
  historico_folios <- readxl::read_xlsx("E:/historico_example.xlsx")
  
  fn <- tabla_fondos[which(tabla_fondos$FONDO == fondo),]$`CLAVE FONDO`
  fond <- ifelse(nchar(fn)==1,paste0("000",fn),ifelse(nchar(fn)==2, paste0("00",fn),
                                                      ifelse(nchar(fn)==3, paste0("0",fn),fn)))
  rg <-tabla_fondos[which(tabla_fondos$REGIÓN == reg),]$CVE_REGION
  region <- ifelse(nchar(rg)==1, paste0("00",rg),ifelse(nchar(rg)==2,paste0("0",rg),rg))
  
  buscada <<- historico_folios %>% 
    dplyr::filter(Fondo==fond,
                  Región == region, Subramo == seguro)
}