Animating 2D random walk trajectory with ggplot in R

I'm trying to create an animation that shows the trajectory of a random walk on the (x,y) plane over time. Each 'step' is a move in either the vertical or horizontal direction, never both. For example, if you start at (0,0) you have only four options: (0,1), (0,-1), (1,0), (-1,0); you can never go from (0,0) to (1,1) in one step.

I've written the random walk generating function to ensure that steps can only be taken across one axis at a time. Here is a regular ggplot without animation of one of these random walks using geom_path() and geom_point():

Random walk with T=100

When I try to animate the walk, however, it shows diagonal lines connecting the points which is impossible.

Animated trajectory

I can't figure out why this is happening. I've tried using geom_line() instead but that doesn't seem to fix the issue. The code for the animation is below:

ggplot(df,aes(x=x,y=y)) + 
  geom_path() +
  geom_point() +
  transition_reveal(along=ite) + # ite: numerical ordered variable in df representing the time from 0:n
  scale_x_continuous(breaks = seq(min(df$x), max(df$x), by = 1)) +
  scale_y_continuous(breaks = seq(min(df$y), max(df$y), by = 1)) +
  coord_fixed() +
  theme(panel.grid.minor = element_blank())