Plotly R + Shiny - plot doesn't refresh, but rather is plotted over

I am using plotly with R to make an app. The plot is produced and plotted, but when I make another selection to create another plot it is plotted above the existing one. How do I fix it? Desired behavior is to have old plot gone and only new being plotted.

App is here :

code is here


pathToFiles <- "."
fileNames <- list.files(pathToFiles, pattern = “_.txt”, recursive = FALSE, include.dirs = FALSE, full.names = TRUE)
fileList <- basename(fileNames)

ui <- fluidPage(
selectInput(inputId = “file”, label = “Select a file”, choices = fileList, selected = “”),

server <- function(input, output)
output$vPlot <- renderPlotly({volcanize(input$file)})

shinyApp (ui = ui, server = server)

volcanize function returns plotly plot with return§.