How to fix or work around apparent bug in plotly's event_data("plotly_hover") when interrogating 3d surface plots

I've produced an app where the aim is to combine four surfaces of values on a common 3D plane, with corresponding subplots that show cross-sections of z ~ y and z ~ x. To do this I'm trying to use event_data("plotly_hover") to extract the x and y values of the surface.

However, the maximum x value recorded by event_data("plotly_hover") is truncated at around 38, whereas the maximum x value is 80. The tooltips for the surface itself, however, are correct.

This is shown in the two figures: the first shows both the tooltip and event_data() output where x < 38, both of which are correct; and the latter shows the tooltip and event_data where x > 38. The tooltip correctly describes the corresponding values, but the event_data output is stuck at the last position where x == 38.

The code is reproduced below (much of which is about the construction of the tooltip). Any suggestions for why event_data is not working correctly in this instance, and suggested solutions (either using event_data or a work-around) are much appreciated.

#
# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#
library(tidyverse)
library(shiny)
library(RColorBrewer)
library(plotly)
read_csv("https://github.com/JonMinton/housing_tenure_explorer/blob/master/data/FRS%20HBAI%20-%20tables%20v1.csv?raw=true") %>% 
#read_csv("data/FRS HBAI - tables v1.csv") %>% 
  select(
    region = regname, year = yearcode, age = age2, tenure = tenurename, n = N_ten4s, N = N_all2
  ) %>% 
  mutate(
    proportion = n / N
  ) -> dta 

regions <- unique(dta$region)

tenure_types <- unique(dta$tenure)


# Define UI for application that draws a histogram
ui <- fluidPage(

   # Application title
   titlePanel("Minimal example"),

   # Sidebar with a slider input for number of bins 
   sidebarLayout(
      sidebarPanel(
         sliderInput("bins",
                     "Number of bins:",
                     min = 1,
                     max = 50,
                     value = 30)
      ),

      # Show a plot of the generated distribution
      mainPanel(
         plotlyOutput("3d_surface_overlaid"),
         verbatimTextOutput("selection")
      )
   )
)

# Define server logic required to draw a histogram
server <- function(input, output) {

  output$`3d_surface_overlaid` <- renderPlotly({
    # Start with a fixed example 

    matrixify <- function(X, colname){
      tmp <- X %>% 
        select(year, age, !!colname)
      tmp %>% spread(age, !!colname) -> tmp
      years <- pull(tmp, year)
      tmp <- tmp %>% select(-year)
      ages <- as.numeric(names(tmp))
      mtrx <- as.matrix(tmp)
      return(list(ages = ages, years = years, vals = mtrx))
    }


    dta_ss <- dta %>% 
      filter(region == "UK") %>% 
      select(year, age, tenure, proportion) 

    surface_oo <- dta_ss %>% 
      filter(tenure == "Owner occupier") %>% 
      matrixify("proportion")

    surface_sr <- dta_ss %>% 
      filter(tenure == "Social rent") %>% 
      matrixify("proportion")

    surface_pr <- dta_ss %>% 
      filter(tenure == "Private rent") %>% 
      matrixify("proportion")

    surface_rf <- dta_ss %>% 
      filter(tenure == "Care of/rent free") %>% 
      matrixify("proportion")


    tooltip_oo <- surface_oo

    tooltip_sr <- surface_sr

    tooltip_pr <- surface_pr

    tooltip_rf <- surface_rf

    custom_text <- paste0(
      "Year: ", rep(tooltip_oo$years, times = length(tooltip_oo$ages)), "\t",
      "Age: ", rep(tooltip_oo$ages, each = length(tooltip_oo$years)), "\n",
      "Composition: ", 
      "OO: ", round(tooltip_oo$vals, 2), "; ",
      "SR: ", round(tooltip_sr$vals, 2), "; ",
      "PR: ", round(tooltip_pr$vals, 2), "; ",
      "Other: ", round(tooltip_rf$vals, 2)
    ) %>% 
      matrix(length(tooltip_oo$years), length(tooltip_oo$ages))

    custom_oo <- paste0(
      "Owner occupation: ", 100 * round(tooltip_oo$vals, 3), " percent\n",
      custom_text
    ) %>% 
      matrix(length(tooltip_oo$years), length(tooltip_oo$ages))

    custom_sr <- paste0(
      "Social rented: ", 100 * round(tooltip_sr$vals, 3), " percent\n",
      custom_text
    ) %>% 
      matrix(length(tooltip_oo$years), length(tooltip_oo$ages))

    custom_pr <- paste0(
      "Private rented: ", 100 * round(tooltip_pr$vals, 3), " percent\n",
      custom_text
    ) %>% 
      matrix(length(tooltip_oo$years), length(tooltip_oo$ages))

    custom_rf <- paste0(
      "Other: ", 100 * round(tooltip_rf$vals, 3), " percent\n",
      custom_text
    ) %>% 
      matrix(length(tooltip_oo$years), length(tooltip_oo$ages))

    n_years <- length(surface_oo$years)
    n_ages <- length(surface_oo$ages)

    plot_ly(
      showscale = F
    ) %>% 
      add_surface(
        x = ~surface_oo$ages, y = ~surface_oo$years, z = surface_oo$vals,
        name = "Owner Occupiers",
        opacity = 0.7,
        colorscale = list(
          c(0,1),
          c('rgb(255,255,0)' , 'rgb(255,255,0)')
        ),
        hoverinfo = "text",
        text = custom_oo

      ) %>% 
      add_surface(
        x = ~surface_sr$ages, y = ~surface_sr$years, z = surface_sr$vals,
        name = "Social renters",
        opacity = 0.7,
        colorscale = list(
          c(0,1),
          c('rgb(255,0,0)' , 'rgb(255,0,0)')
        ),
        hoverinfo = "text",
        text = custom_sr

      ) %>% 
      add_surface(
        x = ~surface_pr$ages, y = ~surface_pr$years, z = surface_pr$vals,
        name = "Private renters",
        opacity = 0.7,
        colorscale = list(
          c(0,1),
          c('rgb(0,255,0)' , 'rgb(0,255,0)')
        ),
        hoverinfo = "text",
        text = custom_pr

      ) %>% 
      add_surface(
        x = ~surface_rf$ages, y = ~surface_rf$years, z = surface_rf$vals,
        name = "Other",
        opacity = 0.7,
        colorscale = list(
          c(0,1),
          c('rgb(0,0,255)' , 'rgb(0,0,255)')
        ),
        hoverinfo = "text",
        text = custom_rf


      ) %>% 
      layout(
        scene = list(
          aspectratio = list(
            x = n_ages / n_years, y = 1, z = 0.5
          ),
          xaxis = list(
            title = "Age in years"
          ),
          yaxis = list(
            title = "Year"
          ),
          zaxis = list(
            title = "Proportion"
          ),
          showlegend = FALSE
        )      )

  })

  output$selection <- renderPrint({
    s <- event_data("plotly_hover")
    if (length(s) == 0){
      "Move around!"
    } else {
      as.list(s)
    }

  })

}

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

from How to fix or work around apparent bug in plotly's event_data("plotly_hover") when interrogating 3d surface plots