Can someone with Alicia's Keys test this...

I believe this only happens on key A3 (I believe that is the correct name...it's the A below middle C).

Seems to happen in plugin, as well as stand alone.

if you press the key with out the sustain pedal pressed as light as you can, it sounds normal...

if you press the key with the sustain pedal down, same velocity, the output is louder with what I will describe as more attack. Almost like there is no velocity layers below a certain point.

 

I just tried it, and yes, I hear it too. It's just one of those minute anomalies of sampling acoustic instruments. When they sampled several velocity layers of each note, barring the use of a robot (which I do not believe they used), it's impossible to guarantee the exact same amount of force was used on every single ppppp sample.

If it really bothers you you can go into Instrument Edit mode and adjust the volume of that sample. (This requires owning the full version of Kontakt.)

 

I thought about that, but because the attack is different, it wouldn't really fix it...the reality is though, when I am playing, even when playing soft, I don't notice it.