When calling on geom_area tooltip activates when hovering over line, not area

Calling ggplotly on ggplot invoking geom_area results in a plot in which the tooltip activates when hovering over the "lines" separating the areas. I would have expected the tooltip to activate when hovered over the filled area.

Here is some reprex

library("ggplot2")
library("plotly")

#create the data
data <- data.frame('year' = rep(1981:2020, 2),
           "type" = rep(c("a", "b"), 40),
           "value" = runif(80))

#Generate the plot
ggplotly(
  ggplot(data, 
         aes(x = year, y = value, fill = type)) +
    geom_area(col = "grey", size = 0.5) #set the line col so that you can see the activation when close to the line
)
  

I don't see any open or closed issues on this. Online, I only see this solution: https://stackoverflow.com/questions/47331323/ggplotly-and-geom-area-display-informations-when-hovering-over-an-area-not-a, which seems convoluted.

Regardless of that solution, I would still assume the expected behavior for geom_area is for the tooltip to activate over the area, not the line.

まず、提供された reprex を R、ggplot2、plotly で実行し、その後、geom_area のホバー動作について ggplotly 変換を調べます。塗りつぶされた領域にホバーしたときにツールチップが有効になり、領域を分ける線上でのみ有効になるのではない状態になれば完了です。