Simulink Zoom FFT - error in native MATLAB example (dspzoomfft)

I am trying to understand the Zoom FFT algorithm, and am playing around with the native MATLAB example for Simulink (opened by typing "dspzoomfft" at the MATLAB command line).

Without changing any parameters, the array plot scope seems to show the wrong result. The 1 kHz sine wave has a smaller amplitude than the 1.4 kHz sine wave, but appears to have a larger magnitude in the scope. Additionally, if I change the 1 kHz sine wave to a frequency of 1.1 kHz, the Zoom FFT output appears to show the same 1 kHz; however, the 1.4 kHz peak is moved to 1.5 kHz.

When I compare a regular FFT to the example data, I get the right frequencies. Is there an error in the example? or am I missing some fundamental aspect about Zoom FFTs?