Empty facets when using subplot on multiple facet plots with shareX = TRUE

When running the code below, the first subplot produces 4 empty facets in the two plotlys while the latter produces no empty facets (expected). I notice that the third and fourth xaxis x3 and x4 do not exist in the plotly object xaxis property in $x$data. It seems to be hard capped at two such that the traces intended for the >2 facets are accumulated into the second facet (x2)

library(tidyverse)
library(plotly)
facet_plot <- ggplotly(
  tibble(x = rnorm(75), y = rnorm(75), type = rep(LETTERS[1:3], 25)) %>%
    ggplot(aes(x, y)) + geom_point() + facet_wrap(~ type))
subplot(facet_plot, facet_plot, nrows = 2, shareX = TRUE)
subplot(facet_plot, facet_plot, nrows = 2)

首先运行包含两个分面图的可复现 R 示例，并比较共享 X 和不共享 X 的子图结果。检查 plotly 对象的 x$data xaxis 条目，尤其是 x3 和 x4；完成标准是共享子图保留所有分面轴，并且不出现空分面。