Hi - I have both X2 Producer and Kontakt with the Alicia Keys library.
I just ran a test of your reported issue, using a new project with the Normal template. I loaded up Kontakt 5 and loaded the Alicia piano, then routed a MIDI track and audio track appropriately to and from Kontakt.
I had no trouble whatsoever in triggering MIDI and hearing proper sound playback through Kontakt and the Alicia Keyes piano.
Please detail the audio track input/output assignments, as well as the MIDI track assignments, and confirm the MIDI channel you have the Alicia Piano loaded into.
My assignments are:
Synth Rack: 1 instance of Kontakt 5. There is a multi-rack loaded with only the Alicia Keyes Piano instrument, and default channel and output assignments were used.
Audio Track: I had 1 audio track in the project, and the input assignment was the stereo output from Kontakt 5, which is what was specified within Kontakt for the loaded Alicia Keyes Piano instrument. Audio track output was to the default Master Bus.
MIDI Track: I had a single MIDI track in the project, and the MIDI Input was left to the default Omni (none). The MIDI Output was assigned to Kontakt 5, which had the Alicia Keyes Piano instrument loaded.
So, I am completely unsure as to why you are having this issue, as it does not appear to happen per the test project I created to test out your reported symptoms.
Bob Bone