hovermode = "common" not displaying correct interval for histogram

[bklingen]

I would have expected the x hover label to read "50 - 100" (or "50 - 99"), but instead it shows "50 - 90". (And is similarly off for the other bins.) Such odd behavior occurs for a variety of datasets, but works correctly for others.

library(plotly)
x <- c(0, 50, 70, 100, 130, 140, 140, 150, 160, 180,
       180, 180, 190, 200, 200, 210, 210, 220, 290, 340)
plot_ly(
  data = data.frame(x=x),
  x = ~x,
  type = "histogram",
  marker = list(line = list(color = 'white', width = 1))
) %>%
  layout(
    xaxis = list(ticks = "outside"), #hoverformat = ".2f"),
    hovermode = "common"
  )

[bklingen]

Same happens in JS:

https://codepen.io/bklingenberg/pen/zYwdaOq?editors=0011

[bklingen]

Continuing discussion in plotly/plotly.js#5848