Strange Vocal Contour wave shape

[Andrew-Infinite]

Not sure if I am paranoid or something, but when I was using the vocal contour mode, my media player just stuck, and when inspecting the waveform with a DAW, it sounded like random noise and zoom out showing a lot of flat area with multiple sudden change in amplitude.

Is this normal? (I did try with another file, I got a empty wave which is 2MB this time where the input is 4MB)

PS: I install with the docker image