glitches in animation made with gganimate

Question

I can't tell if I have an R or a computer issue. When I recreate the demo on gganimate's webpage:

library(gganimate)
p <- ggplot(iris, aes(x = Petal.Width, y = Petal.Length)) + 
  geom_point()
anim = p + 
  transition_states(Species,
                    transition_length = 2,
                    state_length = 1)
anim_save("test.gif")

I get this:

The code runs, but the gif is all glitchy.

Is this an R issue? Or a computer issue? I'm on Windows 10.