XDJ D1 - HotCue/Sampler Switch button on Rekordbox DJ

I can assure you, the SAMPLER mode can be used to trigger samples. I would first suggest you ensure you have the latest firmware (1.13) and drivers (for Windows only), and that you reset the MIDI controls by clicking the MIDI button (in rekordbox) then click the DEFAULTS button at the top right of that window.