Tooltip showing "NA" when facets variable has level with one obs

Tooltip shows "NA" instead of value when using facet_wrap/facet_grid with a categorical variable that has one level with only one observation. The tooltip for the level that has only one observation appears correct. But the tooltip for all other facets shows "NA". This issue occurs only when at least one of the levels of a categorical variable used in facet_wrap has exactly one observation. With two observations per level, the problem disappears.

library(plotly)

d <- data.frame(matrix(nrow = 100, ncol =0))

d$cat1 <- sample(LETTERS[1:4], 100, replace = TRUE, prob = c(0.1, 0.2, 0.65, 0.05))
d$x <- rnorm(100)

ggplotly(
  ggplot(data = d, aes(x = x)) +
    geom_histogram() +
    facet_wrap(cat1 ~ .)
)

Run the supplied R reproducer using ggplotly with facet_wrap and a categorical level containing one observation. Trace how tooltip values are assigned across facets, then verify that the singleton level and all other facets display their expected values rather than "NA".