Trouble with data and axes in sublots (R)

Plotly R, MATLAB, Julia, Net Plotly R
1

I am trying to assemble a set of vertically stacked plots sharing a common x-axis. Some of the panels have a two y-axes, and this seems to be complicating my use of subplot. For example:

library(dplyr)
library(plotly)

p1 <- plot_ly() %>%
  add_lines(x = ~1:4, y = ~rep(1:2, 2))

ay <- list(
  tickfont = list(color = "red"),
  overlaying = "y",
  side = "right",
  title = "second y axis"
)
p2 <- plot_ly() %>%
  add_lines(x = ~1:3, y = ~10*(1:3), name = "slope of 10") %>%
  add_lines(x = ~2:4, y = ~1:3, name = "slope of 1", yaxis = "y2") %>%
  layout(
    title = "Double Y Axis", yaxis2 = ay,
    xaxis = list(title="x")
  )
p1
p2

Results in p1

p1
p1861×613 44.3 KB

and p2

p2
p2861×613 25 KB

I’d like to have exactly those two plots vertically aligned. However subplot(p1, p2, nrows = 2, shareX = TRUE) results in

subplots
subplots861×613 64 KB

After scouring documentation, I believe the problem is my lack of understanding how to specify the domain for the axes. I think I need something like

subplot(p1, p2, nrows = 2, shareX = TRUE) %>%
  layout(yaxis = list(domain = list(y = c(0.5, 1))),
         yaxis2 = list(domain = list(y = c(0, 0.5))))

But that stab in the dark isn’t quite right (and as new user here, I’m not allowed to post a 3rd image). Could someone help me understand how this is supposed to work?