Delayed Actions in Shiny App (Leaflet) with Base Map tiles from Mapbox

I've been developing an R Shiny Application that allows users to view when and where select permit holders can park at a public university. When users select a permit type or interact with a data table, then a leaflet map responds by highlighting or zooming-in to particular location. The initial base map comes from custom tiles designed in Mapbox. Sometimes the user interactions work seamlessly, but often the labels, set view, or highlighted shapes will not respond until the user clicks and drags the map slightly.

Here are screenshots of two examples:

(All of the Mapbox labels are shown after zooming out with a mouse. The Mapbox labels are designed to resize or disappear based on zoom-level. The labels do resize/disappear, but only once you click & drag the map.)

(The highlighted shapes and set view are misaligned when clicking on the reset view buttonReset%20Map%20Button . Everything works properly once the user interacts with the map again.)

I'm not exactly sure what's causing these user-interaction problems, and am hoping someone could explain what's causing this problem. Or better yet, if anyone has any suggestions on how to fix the problem I would greatly appreciate it!

Shiny App:

Rdata file:
www contents:
R Code:

#Mapbox Connection Access Token

options(mapbox.accessToken = 'pk.eyJ1IjoiZWN5cGhlciIsImEiOiJjanZxeHpuYmsxN3cyNGFyaHF1aDE0OTgwIn0.IqjTUny7tRSAeQlCpEAaDQ')

# Packages 


# User Interface Portion

ui <- fluidPage(
              #Function called from Shiny app's UI in order for all other shinyjs functions to work
              #Creates Image Header for App, will be removed when App is placed on GMU server
              div(img(src = "GMU_Map_App_Demo.png", height = "80px", width = "100%", align = "middle")),
              column(width = 4, align = "center",
                          absolutePanel(id = "DataTable_Panel",     
                                                  pickerInput("permit_type",label = "Select Permit:",
                                                            choices = c("Mason Pond Evening (D1AE18)",
                                                                        "Mason Pond F/S (D1FA18)",
                                                                        "Mason Pond Payroll Deductible (PRD1)",
                                                                        "Mason Pond Student (D1SA18)",
                                                                        "Shenandoah Evening (D2AE18)",
                                                                        "Shenandoah F/S (D2FA18)",
                                                                        "Shenandoah Payroll Deductible (PRD2)",
                                                                        "Shenandoah Student (D2SA18)",
                                                                        "Rappahannock F/S (D3FA18)",
                                                                        "Rappahannock Payroll Deductible (PRD3)",
                                                                        "Rappahannock Roof F/S (D3RO18)",
                                                                        "Rappahannock Student (D3SA18)",
                                                                        "F/S 9 Month (FF9M18)",
                                                                        "F/S Annual (FFA18)",
                                                                        "F/S Annual Sticker (FFAS18)",
                                                                        "F/S Semester (FFL18/FFG18)",
                                                                        "F/S Semester Sticker (FFLS18/FFGS18)",
                                                                        "Student 9 Month (FS9M18)",
                                                                        "Student Annual (FSA18)",
                                                                        "Student Annual Sticker (FSAS18)",
                                                                        "Student Semester (FSL18/FSG18)",
                                                                        "Student Semester Sticker (FSLS18/FSGS18)",
                                                                        "Global Center F/S (GCFA18)",
                                                                        "Global Center Student (GCSA18)",
                                                                        "Lot M & P Annual (LMP18)",
                                                                        "Lot M & P Semester (MPL18/MPG18)",
                                                                        "Lot I (RIA18)",
                                                                        "Lot J (RJA18)",
                                                                        "Resident Lite (RLA18)",
                                                                        "Lot R (RRA18)",
                                                                        "Surface Reserved (SS18)",
                                                                        "West Campus Annual (WC18)",
                                                                        "West Campus Semester (WCL18/WCG18)",
                                                                        "Foundation (FT18)",
                                                                        "VA Elected Officials (VSL18)",
                                                                        "Board of Visitors (BOV18)",
                                                                        "Daily General (DG18)",
                                                                        "Evening General (EG18)",
                                                                        "Weekly General (WG18)",
                                                                        "Monthly General (MG18)",
                                                                        "Field House Daily (MOPD18)",
                                                                        "Lot P Daily (LP18)",
                                                                        "Field House Weekly (MOPW)",
                                                                        "Field House Monthly (MOPM)",
                                                                        "West Campus Daily (WCD)",
                                                                        "West Campus Weekly (WCW)",
                                                                        "West Campus Monthly (WCM)",
                                                                        "Lot L & K (LK18)",
                                                                        "Adjunct Lite (ADJ18)",
                                                                        "Weekend (WKND)",
                                                                        "RAC/AFC (TA18)",
                                                                        "Swim Team (TS18)",
                                                                        "Eagle Bank (EB18)"),
                                                            multiple = FALSE, selected = "Mason Pond Evening (D1AE18)", options = list(`actions-box` = TRUE,`none-selected-text` = "Nothing Selected",`live-search` = TRUE)),

                  column(width = 8, leafletOutput("MAP_EXAMPLE", height = "550"),
                         absolutePanel(align = "middle",class = "panel panel-default", fixed = FALSE,
                                       draggable = FALSE, top = 5, left = "auto", right = 25, bottom = "auto",
                                       width = 190, height = 30,

# Define server logic required to draw a histogram
server <- function(input, output) {
#Produce Static Leaflet Map 
  output$MAP_EXAMPLE <- renderLeaflet({ 
  leaflet(options = leafletOptions(dragging = TRUE,
                                     minZoom = 15,
                                     maxZoom = 18)) %>%
      addMapboxGL(style = "mapbox://styles/ecypher/cjwl2kyq92f0m1cqxsq0ymp78", group = 'Mapbox') %>% 
      addProviderTiles('OpenStreetMap',group='OSM') %>% 
      addProviderTiles('Esri.WorldImagery',group='Satellite') %>% 
                       position = "bottomright",
                       options = layersControlOptions(collapsed = TRUE)) %>% 
      setView(lng = -77.314, lat = 38.8320, zoom = 15) %>%  #Complete Zoom Range ~[0:19]
  #User Selects Permit DT
  selected_mapping_permit_type <- reactive({
           "Mason Pond Evening (D1AE18)" = sf_Permit_D1AE18,
           "Mason Pond F/S (D1FA18)" = sf_Permit_D1FA18,
           "Mason Pond Payroll Deductible (PRD1)" = sf_Permit_PRD1,
           "Mason Pond Student (D1SA18)" = sf_Permit_D1SA18,
           "Shenandoah Evening (D2AE18)" = sf_Permit_D2AE18,
           "Shenandoah F/S (D2FA18)" = sf_Permit_D2FA18,
           "Shenandoah Payroll Deductible (PRD2)" = sf_Permit_PRD2,
           "Shenandoah Student (D2SA18)" = sf_Permit_D2SA18,
           "Rappahannock F/S (D3FA18)" = sf_Permit_D3FA18,
           "Rappahannock Payroll Deductible (PRD3)" = sf_Permit_PRD3,
           "Rappahannock Roof F/S (D3RO18)" = sf_Permit_D3RO18,
           "Rappahannock Student (D3SA18)" = sf_Permit_D3SA18,
           "F/S 9 Month (FF9M18)" = sf_Permit_FF9M18,
           "F/S Annual (FFA18)" = sf_Permit_FFA18,
           "F/S Annual Sticker (FFAS18)" = sf_Permit_FFAS18,
           "F/S Semester (FFL18/FFG18)" = sf_Permit_FFL18_FFG18,
           "F/S Semester Sticker (FFLS18/FFGS18)" = sf_Permit_FFLS18_FFGS18,
           "(PRFF)" = sf_Permit_PRFF,
           "Student 9 Month (FS9M18)" = sf_Permit_FS9M18,
           "Student Annual (FSA18)" = sf_Permit_FSA18,
           "Student Annual Sticker (FSAS18)" = sf_Permit_FSAS18,
           "Student Semester (FSL18/FSG18)" = sf_Permit_FSL18_FSG18,
           "Student Semester Sticker (FSLS18/FSGS18)" = sf_Permit_FSLS18_FSGS18,
           "Global Center F/S (GCFA18)" = sf_Permit_GCFA18,
           "Global Center Student (GCSA18)" = sf_Permit_GCSA18,
           "Lot M & P Annual (LMP18)" = sf_Permit_LMP18,
           "Lot M & P Semester (MPL18/MPG18)" = sf_Permit_MPL18_MPG18,
           "Lot I (RIA18)" = sf_Permit_RIA18,
           "Lot J (RJA18)" = sf_Permit_RJA18,
           "Resident Lite (RLA18)" = sf_Permit_RLA18,
           "Lot R (RRA18)" = sf_Permit_RRA18,
           "Surface Reserved (SS18)" = sf_SS18,
           "West Campus Annual (WC18)" = sf_WC18,
           "West Campus Semester (WCL18/WCG18)" = sf_WCL18_WCG18,
           "Foundation (FT18)" = sf_FT18,
           "VA Elected Officials (VSL18)" = sf_VSL18,
           "Board of Visitors (BOV18)" = sf_BOV18,
           "Daily General (DG18)" = sf_DG18,
           "Evening General (EG18)" = sf_EG18,
           "Weekly General (WG18)" = sf_WG18,
           "Monthly General (MG18)" = sf_MG18,
           "Field House Daily (MOPD18)" = sf_MOPD18,
           "Lot P Daily (LP18)" = sf_LP18,
           "Field House Weekly (MOPW)" = sf_MOPW,
           "Field House Monthly (MOPM)" = sf_MOPM,
           "West Campus Daily (WCD)" = sf_WCD,
           "West Campus Weekly (WCW)" = sf_WCW,
           "West Campus Monthly (WCM)" = sf_WCM,
           "Lot L & K (LK18)" = sf_LK18,
           "Adjunct Lite (ADJ18)" = sf_ADJ18,
           "Weekend (WKND)" = sf_WKND,
           "(DP18)" = sf_DP18,
           "(DC18)" = sf_DC18,
           "RAC/AFC (TA18)" = sf_TA18,
           "Swim Team (TS18)" = sf_TS18,
           "Eagle Bank (EB18)" = sf_EB18)
  #Reactive Function subsets the user-selected row of previously chosen Permit DT
    dynamic_marker_df <- reactive({
    #Reactive value stores currently selected Permit DT as `current_selection_df` object
     current_selection_df <- selected_mapping_permit_type()
    #Saves row currently selected by User as `selected_row_id` object
      selected_row_id <- input$Map_DT_rows_selected
    #Subsets selected Permit DT to keep only the User selected row
      dynamic_marker_df <- current_selection_df[selected_row_id,]
  #Reactive function that maps all polygons in user-selected Permit DT

    leafletProxy("MAP_EXAMPLE", data = selected_mapping_permit_type()) %>%
      clearShapes() %>%
      addPolygons(layerId = ~Location,
                  label = ~Popup_Text,
                  color = ~Color,
                  weight = 2,
                  fillColor = ~Color,
                  fillOpacity = 0.35,
                  highlightOptions = highlightOptions(color = "black",
                                                      weight = 2,
                                                      bringToFront = TRUE),
                  #Convoluted Way to Format the HTML Pop-up Text Box
                  labelOptions = labelOptions(
                    style = list('font-weight' = 'normal',
                                 'width' = '160px',
                                 'padding' = "2px 5px 2px 5px",
                                 'border-color' = 'rgba(0,0,0,0.5)'
                    textsize = "12px",
                    direction = 'top')
  #Find Longitude of Location that the user selected on current Permit DT
  extract_marker_lng <- reactive({
    extract_marker_lng <- dynamic_marker_df()
    extract_marker_lng <- extract_marker_lng$Marker_Lng
  #Find Latitude of Location that the user selected on current Permit DT
  extract_marker_lat <- reactive({
    extract_marker_lat <- dynamic_marker_df()
    extract_marker_lat <- extract_marker_lat$Marker_Lat

  leafIcons <- icons(
    iconUrl = "",
    iconWidth = 30, iconHeight = 28,
    iconAnchorX = 0, iconAnchorY = 0)
#Places Icon on Map and Zooms toward Icon
  shift_map <- leafletProxy("MAP_EXAMPLE", data = dynamic_marker_df()) %>%
      clearMarkers() %>%
      addMarkers(lng = ~Marker_Lng,
                 lat = ~Marker_Lat,
                 icon = leafIcons)
   shift_map %>%  setView(lng = extract_marker_lng(),
                          lat = extract_marker_lat(),
                          zoom = 17)

#Change Campus Label Dynamically [Top Right Box]

campus_location_value <- reactive({
  #Stores Center of Map view as a point
  user_center_view <- st_point(c(input$MAP_EXAMPLE_center$lng,input$MAP_EXAMPLE_center$lat))
  #Evaluates if the Center of Map View is within a polygon containing the Boundary of Fairfax Campus
  TF_Fairfax_value <- as.numeric(st_contains(Boundary_Fairfax_Campus,user_center_view))
  TF_Fairfax_value <- if(TF_Fairfax_value %in% NA){TF_Fairfax_value = 0} else {TF_Fairfax_value = 1}
  #Evaluates if the Center of Map View is within a polygon containing the Boundary of Sci-Tech Campus
  TF_Sci_Tech_value <- as.numeric(st_contains(Boundary_Sci_Tech_Campus,user_center_view))
  TF_Sci_Tech_value <- if(TF_Sci_Tech_value %in% NA){TF_Sci_Tech_value = 0} else {TF_Sci_Tech_value = 1}
  #Evaluates if the Center of Map View is within a polygon containing the Boundary of Arlington Campus
  TF_Arlington_value <- as.numeric(st_contains(Boundary_Arlington_Campus,user_center_view))
  TF_Arlington_value <- if(TF_Arlington_value %in% NA){TF_Arlington_value = 0} else {TF_Arlington_value = 1}

  #Boolean Values Pasted Together to create code indenifying the appropiate campus label to display
  campus_location_ID <- paste0(TF_Fairfax_value,TF_Sci_Tech_value,TF_Arlington_value)
  campus_location_value <- switch (campus_location_ID,
                                   "100" = "Fairfax Campus",
                                   "010" = "Sci-Tech Campus",
                                   "001" = "Arlington Campus")


#Function that actually produces the dynamic, upper-right campus label

output$Campus_Label <- renderUI({
    style="font-size: 20px; position: relative;top: 50%;transform: translateY(-1%)",
    HTML(markdownToHTML(fragment.only=TRUE, text=c(paste0(campus_location_value()))))

#Renders and formats the selected Permit DT

output$Map_DT  <-  renderDataTable({
  datatable(selected_mapping_permit_type(), rownames = FALSE,
            escape = FALSE,
            selection = "single",
            extensions = c('Scroller',"RowGroup"),
            options = list(pageLength = 100,
                           columnDefs = list(list(visible = FALSE,targets = c(2:7)),
                                             list(width = '50%', targets = c(0)),
                                             list(width = '50%', targets = c(1))),
                            scrollY = "400px",
                           rowGroup = list(dataSrc = 6),
                           scrollCollapse = TRUE,
                          dom = 't', ordering = FALSE))


# Run the application 
shinyApp(ui = ui, server = server)