Since I updated ggplot2 to version 4.0.0, panel.border() is ignored when a ggplot is passed to ggplotly()
In older versions of ggplot2 (v3.5.2), the border appears as expected.
Here is the code to reproduce the bug:
library(ggplot2)
library(plotly)
df <- data.frame(x = c(1:10), y = c(1:10))
p <- ggplot(df, aes(x, y)) +
geom_point() +
theme(panel.border = element_rect(color = 2, fill = NA))
ggplotly(p)