Italicizing strip.text with ggplotly

I've been trying to get the labels on a faceted grid to be italicized on the y-axis and can't seem to make it to happen.

Here I'll use the "Free Y Axis" example of a faceted grid as written by Plotly:
https://plotly.com/ggplot2/facet_grid/

The only change I've made to this code is make the strip text for both axes larger and the y-axis text italicized in the ggplot theme().

library(reshape2)
library(ggplot2)
library(plotly)

p <- ggplot(tips, aes(x=total_bill)) + geom_histogram(binwidth=2,colour="white")

# With panels that have the same scaling, but different range (and therefore different physical sizes)
p <- p + facet_grid(sex ~ smoker, scales="free", space="free") +
               theme(strip.text.x = element_text(size = 13),
               strip.text.y = element_text(size = 13,face = "italic"))

p

fig <- ggplotly(p)

fig

The plot produced by ggplot (p) looks like this, with the y-axis facet labels in italics:

The plot produced by ggplotly (fig) looks like this:

Any clarification if I'm missing something would be appreciated. Thank you!

Beginne mit dem bereitgestellten Beispiel „Free Y Axis“ und vergleiche das ggplot-Objekt p mit dem ggplotly-Ergebnis fig. Konzentriere dich dabei darauf, wie die Gestaltung des Facet-Strip-Texts konvertiert wird. Stelle die fehlende kursive Gestaltung der Facet-Beschriftungen der y-Achse wieder her. Als abgeschlossen gilt die Aufgabe, wenn ggplotly den kursiven Schriftschnitt beibehält und gleichzeitig den größeren Strip-Text bewahrt.