Make sure your keyboard is set to the same channel as the omni (forget what it’s actually called) track (default ch11) Chromatics are from C5 +2 octaves. It’s really not much room for playing samples chromatically. It’s definitely not one of OT’s strong points.
Hoping for a future release with a granular/chromatic/single cycle based machine, which allows a bigger range of play without resorting to playback tricks.