Multiple lines in one figure with MacOSX backend

I’m trying to plot multiple lines like this on macOS:

from matplotlib import pyplot as plt
plt.plot([0,1], [2,3])
plt.plot([0,1], [4,1])

This only shows the first line. If I switch the backend to something other than "MacOSX", this works. Is this expected behavior for the default backend on macOS? What am I missing?

Are you running a script or in an interactive terminal? If you resize the window, does the second line show up?