Setting anchor = "free" in R subplot() causes the graph to disappear

I'm trying to build a subplot of stacked scatter plots, where there are multiple axes on each scatter plot.

Below is an example of the type of plot. To position the yaxis side-by-side, I have layout(yaxis(anchor = "free")) set am using position to place the axis.

All my attempts to set anchor = "free" in subplots left my plot space completely blank. Some testing revealed that even a subplot constructed from a single plot will not display if anchor="free"

Please see below REPREX.

require(plotly)
df <- data.frame(x = 1:10, y = 1:10, y2 = 10:19)
plt <- plot_ly(data = df) %>%
  add_trace(x = ~x, y = ~y,
            mode = "markers", type = "scatter",
            yaxis = "y") %>%
  add_trace(x = ~x, y = ~y2,
            mode = "markers", type = "scatter",
            yaxis = "y2") %>%
  layout(
    xaxis = list(
      domain = c(.12, .88)
    ),
    yaxis = list(
      title = "y_1"
    ),
    yaxis2 = list(
      title = "y_2",
      anchor = "free",
      position = .10,
      overlaying = "y"
    ),
    margin = list(
      pad = 60
    )
  )
subplot(plt)

Commencez par exécuter le reprex R fourni avec plot_ly(), layout() et subplot() afin de confirmer que anchor = "free" produit un graphique vide. Examinez ensuite la manière dont subplot() gère les paramètres de yaxis et yaxis2, en particulier anchor, position et overlaying. Le travail est terminé lorsque le subplot affiche ses traces tout en conservant l’axe positionné librement.