So I noticed a shift in the waveform when adding this effect, it's a minor but noticeable lift to the midtones and highlights. Narrowed it down to the hue/saturation filter. Managed to reproduce this on other effects and computers so probably a bug. I have filed a bug report with Apple and hopefully this is fixed in the next update.
In the meantime here is a version with the saturation disabled. You can re-enable it with the saturation checkbox.