Boxplot in AoG acting weirdly

Hi all.

I am currently using AlgebraOfGraphics (with CairoMakie backend).

Was running thru the PalmerPenguin data set and was trying to plot and I ran into a problem. I have removed all missing entries prior to plotting.

So basically

using PalmerPenguins
using DataFrames

penguin = DataFrame(PalmerPenguins.load())
penguin_complete = penguin[findall(completecases(penguin)), :]

plt = data(penguins_complete) *
        mapping(:species, :body_mass_g, color=:island, dodge=:island) *
        visual(BoxPlot)
draw(plt)

I got the following. As you can see from below, the species “Gentoo” did not appear.

Can someone please help me with this issue? Thank you!