Improper alignment of boxplots in facets

Hi,
first of all, thanks for a great package!
I have spent some time with it recently and I think that I have found a bug. If I use boxplots and facets, the boxplots in the upper facet are on the left side of the category while the boxplots in the bottom facet are on the right side of the category, while I believe that they should be aligned in the middle. Picture tells more than thousands words, so see bellow...

you can get it with the following code:

library(ggplot2)
library(plotly)

data.1 <- diamonds
data.1$set <- "set1"

data.2 <- data.1
data.2$set <- "set2"

my.data <- rbind(data.1, data.2)

p <- ggplot(my.data, aes(x=cut, y=price, fill= clarity))+
  geom_boxplot()+
  facet_grid(set ~ .)

ggplotly(p)%>%
  layout(boxmode = "group")

从提供的 ggplot2 和 ggplotly 复现示例开始，重点关注分面箱线图的转换和定位方式。重现该示例，并验证两个分面中的箱线图都以其类别为中心，同时保留分组布局行为。