@MadhuSharma Just a short update: I ran into some unrelated problems, so it might take a bit longer to release the update. Your suggestions make a lot of sense, so I'll definitely add them.
@indernagra I was able to reproduce the problem when using "Suitable for voice" quality. I'll look into this.
For now, changing the quality setting should make it work again. Please let me know if it doesn't.
@indernagra What speed are you using? What version of macOS/iTunes are you using? What quality setting do you use and does it still happen if you change it. (Speed-Up > Preferences... > General)
@Mathew_Lucas Thank you. The problem is the algorithm. I added an option to use a different one that might work better. The update should be available in a few days (or after the holidays, depending on App Review).