`expression(list())` introduced when using labeller in facet

[meldarionqeusse]

When I am using labeller in facet_wrap I am getting expression(list()) showing up with ggplotly.

mtcars$cyl2 <- factor(mtcars$cyl, labels = c("alpha", "beta", "gamma"))
p <- ggplot(mtcars, aes(wt, mpg)) + geom_point()

ggplotly(p + facet_wrap(. ~cyl)) # See figure 1

ggplotly(p + facet_wrap(. ~cyl, labeller = label_wrap_gen(width = 25, multi_line = FALSE))) #see figure2

Figure 1

Figure 2